1
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Almannai M, Marafi D, Zaki MS, Maroofian R, Efthymiou S, Saadi NW, Filimban B, Dafsari HS, Rahman F, Maqbool S, Faqeih E, Al Mutairi F, Alsharhan H, Abdelaty O, Bin-Hasan S, Duan R, Noureldeen MM, Alqattan A, Houlden H, Hunter JV, Posey JE, Lupski JR, El-Hattab AW. Expanding the phenotype of PPP1R21-related neurodevelopmental disorder. Clin Genet 2024; 105:620-629. [PMID: 38356149 PMCID: PMC11065596 DOI: 10.1111/cge.14492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/16/2024]
Abstract
PPP1R21 encodes for a conserved protein that is involved in endosomal maturation. Biallelic pathogenic variants in PPP1R21 have been associated with a syndromic neurodevelopmental disorder from studying 13 affected individuals. In this report, we present 11 additional individuals from nine unrelated families and their clinical, radiological, and molecular findings. We identified eight different variants in PPP1R21, of which six were novel variants. Global developmental delay and hypotonia are neurological features that were observed in all individuals. There is also a similar pattern of dysmorphic features with coarse faces as a gestalt observed in several individuals. Common findings in 75% of individuals with available brain imaging include delays in myelination, wavy outline of the bodies of the lateral ventricles, and slight prominence of the bodies of the lateral ventricles. PPP1R21-related neurodevelopmental disorder is associated with a consistent phenotype and should be considered in highly consanguineous individuals presenting with developmental delay/intellectual disability along with coarse facial features.
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Affiliation(s)
- Mohammed Almannai
- Genetics and Precision Medicine department (GPM), King
Abdullah Specialized Children’s Hospital (KASCH), King Abdulaziz Medical
City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
- Medical Genomics Research Department, King Abdullah
International Medical Research Center, Ministry of National Guard Health Affairs,
King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard
Health Affairs, Riyadh, Saudi Arabia
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, 77030, USA
- Department of Pediatrics, College of Medicine, Kuwait
University, P.O. Box 24923, 13110 Safat, Kuwait
| | - Maha S. Zaki
- Clinical Genetics Department, Human Genetics and Genome
Research Institute National Research Centre, Cairo, Egypt
- Genetics Department, Armed Forces College of Medicine
(AFCM), Cairo, Egypt
| | - Reza Maroofian
- Department of Neuromuscular disorders, UCL Queen Square
Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Stephanie Efthymiou
- Department of Neuromuscular disorders, UCL Queen Square
Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Nebal Waill Saadi
- College of Medicine, University of Baghdad, Pediatric
Neurology, Children Welfare Teaching Hospital, Baghdad, Iraq
| | - Bilal Filimban
- Section of Medical Genetics, Children’s Hospital,
King Fahad Medical City, Riyadh, Saudi Arabia
| | - Hormos Salimi Dafsari
- Department of Pediatrics, Center for Rare Diseases,
Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne,
Germany
- Randall Centre for Cell and Molecular Biophysics,
Faculty of Life Sciences and Medicine (FoLSM), King’s College London, London,
United Kingdom
- Max-Planck-Institute for Biology of Ageing, Cologne,
Germany
- Cologne Excellence Cluster on Cellular Stress Responses
in Aging Associated Diseases (CECAD), Cologne, Germany
| | - Fatima Rahman
- Department of Developmental - Behavioral Pediatrics,
University of Child Health Sciences & The Children’s Hospital, Lahore,
Pakistan
| | - Shazia Maqbool
- Department of Developmental - Behavioral Pediatrics,
University of Child Health Sciences & The Children’s Hospital, Lahore,
Pakistan
| | - Eissa Faqeih
- Section of Medical Genetics, Children’s Hospital,
King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fuad Al Mutairi
- Genetics and Precision Medicine department (GPM), King
Abdullah Specialized Children’s Hospital (KASCH), King Abdulaziz Medical
City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
- Medical Genomics Research Department, King Abdullah
International Medical Research Center, Ministry of National Guard Health Affairs,
King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard
Health Affairs, Riyadh, Saudi Arabia
| | - Hind Alsharhan
- Department of Pediatrics, College of Medicine, Kuwait
University, P.O. Box 24923, 13110 Safat, Kuwait
- Department of Pediatrics, Farwaniya Hospital, Ministry
of Health, Sabah Al-Nasser, 92426, Kuwait
- Kuwait Medical Genetics Center, Ministry of Health,
Sulaibikhat, 80901, Kuwait
- Department of Genetic Medicine, Johns Hopkins University
School of Medicine, Baltimore, MD, USA
| | - Omar Abdelaty
- Department of Pediatrics, Farwaniya Hospital, Ministry
of Health, Sabah Al-Nasser, 92426, Kuwait
| | - Saadoun Bin-Hasan
- Department of Pediatrics, Farwaniya Hospital, Ministry
of Health, Sabah Al-Nasser, 92426, Kuwait
| | - Ruizhi Duan
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, 77030, USA
| | - Mahmoud M. Noureldeen
- Department of Pediatrics, Faculty of Medicine, Beni-Suef
University, Beni-Suef, Egypt
| | - Alaa Alqattan
- Department of Pediatrics, Farwaniya Hospital, Ministry
of Health, Sabah Al-Nasser, 92426, Kuwait
| | - Henry Houlden
- Department of Neuromuscular disorders, UCL Queen Square
Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Jill V Hunter
- Texas Children Hospital, Houston, Texas, 77030,
USA
- Department of Radiology, Baylor College of Medicine,
Houston, Texas, 77030
| | - Jennifer E. Posey
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, 77030, USA
| | - James R. Lupski
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, 77030, USA
- Texas Children Hospital, Houston, Texas, 77030,
USA
- Human Genome Sequencing Center, Baylor College of
Medicine, Houston, Texas, 77030, USA
- Department of Pediatrics, Baylor College of Medicine,
Houston, Texas, 77030, USA
| | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine,
University of Sharjah, Sharjah, United Arab Emirates
- Genetics Clinics, University Hospital Sharjah, Sharjah,
United Arab Emirates
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Husain RA, Jiao X, Hennings JC, Giesecke J, Palsule G, Beck-Wödl S, Osmanović D, Bjørgo K, Mir A, Ilyas M, Abbasi SM, Efthymiou S, Dominik N, Maroofian R, Houlden H, Rankin J, Pagnamenta AT, Nashabat M, Altwaijri W, Alfadhel M, Umair M, Khouj E, Reardon W, El-Hattab AW, Mekki M, Houge G, Beetz C, Bauer P, Putoux A, Lesca G, Sanlaville D, Alkuraya FS, Taylor RW, Mentzel HJ, Hübner CA, Huppke P, Hart RP, Haack TB, Kiledjian M, Rubio I. Biallelic NUDT2 variants defective in mRNA decapping cause a neurodevelopmental disease. Brain 2024; 147:1197-1205. [PMID: 38141063 PMCID: PMC10994549 DOI: 10.1093/brain/awad434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/08/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Dysfunctional RNA processing caused by genetic defects in RNA processing enzymes has a profound impact on the nervous system, resulting in neurodevelopmental conditions. We characterized a recessive neurological disorder in 18 children and young adults from 10 independent families typified by intellectual disability, motor developmental delay and gait disturbance. In some patients peripheral neuropathy, corpus callosum abnormalities and progressive basal ganglia deposits were present. The disorder is associated with rare variants in NUDT2, a mRNA decapping and Ap4A hydrolysing enzyme, including novel missense and in-frame deletion variants. We show that these NUDT2 variants lead to a marked loss of enzymatic activity, strongly implicating loss of NUDT2 function as the cause of the disorder. NUDT2-deficient patient fibroblasts exhibit a markedly altered transcriptome, accompanied by changes in mRNA half-life and stability. Amongst the most up-regulated mRNAs in NUDT2-deficient cells, we identified host response and interferon-responsive genes. Importantly, add-back experiments using an Ap4A hydrolase defective in mRNA decapping highlighted loss of NUDT2 decapping as the activity implicated in altered mRNA homeostasis. Our results confirm that reduction or loss of NUDT2 hydrolase activity is associated with a neurological disease, highlighting the importance of a physiologically balanced mRNA processing machinery for neuronal development and homeostasis.
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Affiliation(s)
- Ralf A Husain
- Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
| | - Xinfu Jiao
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | | | - Jan Giesecke
- Department of Anaesthesiology and Intensive Care Medicine, Jena University Hospital, Member of the Leibniz Center for Photonics in Infection Research (LPI), 07747 Jena, Germany
| | - Geeta Palsule
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Stefanie Beck-Wödl
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Dina Osmanović
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| | - Kathrine Bjørgo
- Department of Medical Genetics, Oslo University Hospital, 0424 Oslo, Norway
| | - Asif Mir
- Department of Biological Sciences, Faculty of Sciences, International Islamic University, Islamabad 44000, Pakistan
| | - Muhammad Ilyas
- Department of Biological Sciences, Faculty of Sciences, International Islamic University, Islamabad 44000, Pakistan
| | - Saad M Abbasi
- Department of Biological Sciences, Faculty of Sciences, International Islamic University, Islamabad 44000, Pakistan
| | - Stephanie Efthymiou
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Natalia Dominik
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Reza Maroofian
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Julia Rankin
- Department of Clinical Genetics, Royal Devon University Hospital, Exeter, EX1 2ED, UK
| | - Alistair T Pagnamenta
- Oxford NIHR Biomedical Research Centre, Wellcome Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Marwan Nashabat
- Medical Genomics Research Department, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Waleed Altwaijri
- Department of Pediatrics, Neurology Division, King Abdullah Specialist Children’s Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Majid Alfadhel
- Medical Genomics Research Department, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
- Genetics and Precision Medicine Department, King Abdullah Specialized Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | - Ebtissal Khouj
- Department of Translational Genomics, Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | | | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, 27272, Sharjah, United Arab Emirates
- Department of Pediatrics, University Hospital Sharjah, 72772, Sharjah, United Arab Emirates
| | - Mohammed Mekki
- Department of Pediatrics, University Hospital Sharjah, 72772, Sharjah, United Arab Emirates
| | - Gunnar Houge
- Department of Medical Genetics, Haukeland University Hospital, 5021 Bergen, Norway
| | | | | | - Audrey Putoux
- Groupement Hospitalier Est, Hospices Civils de Lyon, Service de Génétique, Centre de Référence Anomalies du Développement, 69677 Bron Cedex, France
- Équipe GENDEV, Centre de Recherche en Neurosciences de Lyon, Univ Lyon, Univ Lyon 1, INSERM U1028 CNRS UMR5292, 69008 Lyon, France
| | - Gaetan Lesca
- Groupement Hospitalier Est, Hospices Civils de Lyon, Service de Génétique, Centre de Référence Anomalies du Développement, 69677 Bron Cedex, France
- Physiopathologie et Génétique du Neurone et du Muscle, Univ Lyon, Univ Lyon 1, CNRS, INSERM, UMR5261, U1315, Institut NeuroMyoGène, 69008 Lyon, France
| | - Damien Sanlaville
- Groupement Hospitalier Est, Hospices Civils de Lyon, Service de Génétique, Centre de Référence Anomalies du Développement, 69677 Bron Cedex, France
- Physiopathologie et Génétique du Neurone et du Muscle, Univ Lyon, Univ Lyon 1, CNRS, INSERM, UMR5261, U1315, Institut NeuroMyoGène, 69008 Lyon, France
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE1 4LP, UK
| | - Hans-Joachim Mentzel
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
- Section of Pediatric Radiology, Department of Radiology, Jena University Hospital, 07747 Jena, Germany
| | - Christian A Hübner
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
- Institute of Human Genetics, Jena University Hospital, 07747 Jena, Germany
| | - Peter Huppke
- Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
| | - Ronald P Hart
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Megerditch Kiledjian
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | - Ignacio Rubio
- Department of Anaesthesiology and Intensive Care Medicine, Jena University Hospital, Member of the Leibniz Center for Photonics in Infection Research (LPI), 07747 Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, 07747 Jena, Germany
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3
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Khalaf T, Al Ojaimi M, Saleh DA, Sulaiman A, Sohal AP, Khan A, El-Hattab AW. The utility of exome sequencing in diagnosing pediatric neurodevelopmental disorders in a highly consanguineous population. Clin Genet 2024. [PMID: 38438125 DOI: 10.1111/cge.14508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/06/2024]
Abstract
Exome sequencing (ES) has been utilized in diagnosing children with neurodevelopmental manifestations, this study aimed to investigate the utility of ES in children within a highly consanguineous population that presented with neurodevelopmental complaints. A retrospective chart review was performed for 405 children with neurodevelopmental complaints who have had ES and were evaluated in multiple centers in the United Arab Emirates over a four-year period. Within the cohort of 405 children, consanguinity was reported in 35% (144/405). The primary clinical presentations were developmental delay/cognitive impairment, distinctive facial features, hypotonia, seizures, and weakness. The diagnostic yield was 57% (231/405). Novel variants were identified in 54% (125/231) of positive cases. Within the positive cases, specific treatment was available in 6% (13/231) and copy number variants (CNV) were reported in 3% (8/231) of cases. In eight children, variants in genes that have not yet been linked to human disease that could potentially be the cause of the observed phenotype "candidate genes" were identified. ES was utilized effectively within this cohort with a high diagnostic yield and through the identification of novel gene variants, CNVs, candidate genes and secondary findings as well as the alteration of the treatment plan in cases where treatment was available.
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Affiliation(s)
- Tamam Khalaf
- Genetic Counseling Division, Igenomix, Dubai, UAE
| | - Mode Al Ojaimi
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE
- Department of Pediatrics, University Hospital Sharjah, Sharjah, UAE
| | - Dina Amin Saleh
- Pediatric Neurology Division, American Center for Psychiatry and Neurology, Abu Dhabi, UAE
- Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Alena Sulaiman
- Pediatric Division, KidsHeart Medical Center, Abu Dhabi, UAE
| | - Aman P Sohal
- Pediatric Neurology Division, Neuropedia Children's Neuroscience Center, Dubai, UAE
- Pediatric Neurology Division, Al Qassimi Women and Children's Hospital, Sharjah, UAE
| | - Arif Khan
- Pediatric Neurology Division, Neuropedia Children's Neuroscience Center, Dubai, UAE
- Pediatric Division, Kings College Hospital London, Dubai, UAE
- Pediatric Neurology Division, Kids Neuro Clinic and Rehab Center, Dubai, UAE
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE
- Department of Pediatrics, University Hospital Sharjah, Sharjah, UAE
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Khair H, Hilary S, Al Awar S, Zareba K, Maki S, Sayed G, Mutare S, El-Hattab AW, Al Ibrahim AH. Perinatal Outcomes in Foetuses with Increased Nuchal Translucency and Normal Karyotype: A Retrospective Cohort Study from the United Arab Emirates. J Clin Med 2023; 12:6358. [PMID: 37835002 PMCID: PMC10573960 DOI: 10.3390/jcm12196358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/15/2023] Open
Abstract
This retrospective case-controlled study analysed the outcome of pregnancies with first-trimester enlarged nuchal translucency (NT) and a normal karyotype. A total of 479 pregnancies with first-trimester NT measurements were grouped as control (370 cases; normal NT) and study (109 cases; enlarged NT, ≥95th percentile; with normal karyotype). Adverse outcomes included miscarriage, intrauterine foetal death, termination of pregnancy, neonatal death, and structural/chromosomal/genetic abnormalities. The study was conducted between June 2016 and June 2022 at the Foetal Maternal Unit of Kanad Hospital, UAE. Overall, the live birth rate in the study group was significantly lower (74.3%) compared to the control (94.1%, p < 0.001). All pregnancy outcomes of this group significantly differed compared to the control. The observed miscarriage level was 9.2% (vs. 1.1%, p < 0.001), intrauterine foetal death was 2.8% (vs. 0%, p = 0.001), spontaneous preterm birthwas 11% (vs. 4.9%, p = 0.020), and termination of pregnancy was 3.7% (vs. 0%, p < 0.001). The presence of foetal abnormalities was also significantly higher in the enlarged NT group at 21% (vs. 3.3%, p < 0.001). Results indicate that enlarged NT is associated with adverse pregnancy outcomes even when the karyotype is normal. Based on these results, a comprehensive review of the guidelines for counselling and managing pregnancies with enlarged NT and a normal karyotype is recommended.
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Affiliation(s)
- Howaida Khair
- Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates (K.Z.)
| | - Serene Hilary
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (S.H.)
| | - Shamsa Al Awar
- Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates (K.Z.)
| | - Kornelia Zareba
- Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates (K.Z.)
| | - Sara Maki
- Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates (K.Z.)
| | - Gehan Sayed
- Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates (K.Z.)
| | - Sharon Mutare
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (S.H.)
| | - Ayman W. El-Hattab
- Fetal Maternal Unit, Kanad Hospital, Al Ain P.O. Box 1016, United Arab Emirates
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates
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5
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Xie MJ, Cromie GA, Owens K, Timour MS, Tang M, Kutz JN, El-Hattab AW, McLaughlin RN, Dudley AM. Constructing and interpreting a large-scale variant effect map for an ultrarare disease gene: Comprehensive prediction of the functional impact of PSAT1 genotypes. PLoS Genet 2023; 19:e1010972. [PMID: 37812589 PMCID: PMC10561871 DOI: 10.1371/journal.pgen.1010972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/13/2023] [Indexed: 10/11/2023] Open
Abstract
Reduced activity of the enzymes encoded by PHGDH, PSAT1, and PSPH causes a set of ultrarare, autosomal recessive diseases known as serine biosynthesis defects. These diseases present in a broad phenotypic spectrum: at the severe end is Neu-Laxova syndrome, in the intermediate range are infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end is childhood disease with intellectual disability. However, L-serine supplementation, especially if started early, can ameliorate and in some cases even prevent symptoms. Therefore, knowledge of pathogenic variants can improve clinical outcomes. Here, we use a yeast-based assay to individually measure the functional impact of 1,914 SNV-accessible amino acid substitutions in PSAT. Results of our assay agree well with clinical interpretations and protein structure-function relationships, supporting the inclusion of our data as functional evidence as part of the ACMG variant interpretation guidelines. We use existing ClinVar variants, disease alleles reported in the literature and variants present as homozygotes in the primAD database to define assay ranges that could aid clinical variant interpretation for up to 98% of the tested variants. In addition to measuring the functional impact of individual variants in yeast haploid cells, we also assay pairwise combinations of PSAT1 alleles that recapitulate human genotypes, including compound heterozygotes, in yeast diploids. Results from our diploid assay successfully distinguish the genotypes of affected individuals from those of healthy carriers and agree well with disease severity. Finally, we present a linear model that uses individual allele measurements to predict the biallelic function of ~1.8 million allele combinations corresponding to potential human genotypes. Taken together, our work provides an example of how large-scale functional assays in model systems can be powerfully applied to the study of ultrarare diseases.
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Affiliation(s)
- Michael J. Xie
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
- Molecular Engineering Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Gareth A. Cromie
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
| | - Katherine Owens
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
- Department of Applied Mathematics, University of Washington, Seattle, Washington, United States of America
| | - Martin S. Timour
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
| | - Michelle Tang
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
| | - J. Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, Washington, United States of America
| | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | | | - Aimée M. Dudley
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
- Molecular Engineering Graduate Program, University of Washington, Seattle, Washington, United States of America
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6
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Almahmoud R, Mekki M, El-Hattab AW. Cerebral folate deficiency: A report of two affected siblings. Mol Genet Metab Rep 2023; 35:100975. [PMID: 37101857 PMCID: PMC10123369 DOI: 10.1016/j.ymgmr.2023.100975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/08/2023] [Accepted: 04/09/2023] [Indexed: 04/28/2023] Open
Abstract
Cerebral folate deficiency (CFD) is a rare progressive neurological condition characterized by normal blood folate level and low 5-methyltetrahydrofolate (5-MTHF) levels in the cerebrospinal fluid. Patients present with different neurological findings including hypotonia and microcephaly. Later, patients develop ataxia, seizures, para or quadri-plagia. Herein, we report two siblings; born to consanguineous parents; who had normal neurological development in early childhood. Subsequently they developed drug-resistant seizures, neurological regression, and spastic quadriplegia. After thorough investigations patients had brain MRI which showed abnormal white matter signals and ventricular dilatation, CSF with low 5-MTHF, and whole exome sequencing (WES) revealed a novel homozygous variant in FOLR1 (c.245A > G; p.Tyr82Cys) consistent with the diagnosis of cerebral folate deficiency. They were treated with folinic acid in addition to standard anti-seizure medications. WES aids in reaching CFD diagnosis due to FOLR1 pathogenic variants. These results can be used for future counselling to prevent recurrence in future pregnancies by preimplantation genetic testing prior to implanting the embryo in the uterus. Treatment with folinic acid was shown to improve the neurological symptoms namely reduced the seizures and spasticity.
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Affiliation(s)
- Rabah Almahmoud
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Corresponding author at: College of Medicine, University of Sharjah, PO BOX 27272, Sharjah, United Arab Emirates.
| | - Mohammed Mekki
- Department of Pediatrics, AlQassimi Women and Children Hospital, Sharjah, United Arab Emirates
| | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
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Adachi T, El-Hattab AW, Jain R, Nogales Crespo KA, Quirland Lazo CI, Scarpa M, Summar M, Wattanasirichaigoon D. Enhancing Equitable Access to Rare Disease Diagnosis and Treatment around the World: A Review of Evidence, Policies, and Challenges. Int J Environ Res Public Health 2023; 20:4732. [PMID: 36981643 PMCID: PMC10049067 DOI: 10.3390/ijerph20064732] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
This document provides a comprehensive summary of evidence on the current situation of rare diseases (RDs) globally and regionally, including conditions, practices, policies, and regulations, as well as the challenges and barriers faced by RD patients, their families, and caregivers. The document builds on a review of academic literature and policies and a process of validation and feedback by a group of seven experts from across the globe. Panelists were selected based on their academic merit, expertise, and knowledge regarding the RD environment. The document is divided into five main sections: (1) methodology and objective; (2) background and context; (3) overview of the current situation and key challenges related to RDs covering six dimensions: burden of disease, patient journey, social impact, disease management, RD-related policies, and research and development; (4) recommendations; and (5) conclusions. The recommendations are derived from the discussion undertaken by the experts on the findings of this review and provide a set of actionable solutions to the challenges and barriers to improving access to RD diagnosis and treatment around the world. The recommendations can support critical decision-making, guiding efforts by a broad range of RDs stakeholders, including governments, international organizations, manufacturers, researchers, and patient advocacy groups.
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Affiliation(s)
- Takeya Adachi
- Department of Dermatology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Department of Medical Regulatory Science, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
- United Japanese-Researchers Around-the-World (UJA), Isehara 259-1143, Japan
| | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- MENA (Middle East and North Africa) Organization for Rare Diseases, Dubai 500767, United Arab Emirates
- Department of Pediatrics, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
| | - Ritu Jain
- Dystrophic Epidermolysis Bullosa Research Association (DEBRA), Singapore 059811, Singapore
- Asia Pacific Alliance of Rare Disease Organizations (APARDO), Singapore 188976, Singapore
- Language and Communication Centre, School of Humanities and Social Sciences, Nanyang Technological University, Singapore 639798, Singapore
| | | | - Camila I. Quirland Lazo
- Health Technology Assessment Unit, Cancer Research Department, Arturo López Perez Foundation, Santiago 7500921, Chile
- School of Medicine, Universitat Autònoma de Barcelona, 080193 Barcelona, Spain
- Faculty of Pharmaceutical and Chemical Sciences, University of Chile, Santiago 8380000, Chile
| | - Maurizio Scarpa
- European Reference Network for Hereditary Metabolic Diseases (MetabERN), 33100 Udine, Italy
- Regional Coordinating Center for Rare Diseases Friuli Venezia Giulia, Udine University Hospital, 33100 Udine, Italy
- Brains for Brain Foundation, 35128 Padova, Italy
| | - Marshall Summar
- The Translational Science Training Program, National Institutes of Health (NIH), Maryland, MD 20814, USA
- Children’s National Medical Centre, Washington, DC 20010, USA
- National Organization for Rare Disorders (NORD), Quincy, MA 02169, USA
- Children’s National Rare Disease Institute, Washington, DC 20012, USA
- Department of Pediatrics, George Washington University, Washington, DC 20052, USA
| | - Duangrurdee Wattanasirichaigoon
- Thai Rare Disease Foundation (ThaiRDF), Bangkok 10230, Thailand
- Prader-Willi Syndrome Association (PWSA) of Thailand, Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
- Rare Disease Working Committee, Thai National Health Security Office (NHSO), Bangkok 10210, Thailand
- Sub-Working Committee for Rare Disease Medicine, Thailand National List of Essential Medicines (NLEM), National Drug Policy Division, Food and Drug Administration, Nonthaburi 11000, Thailand
- Medical Genetics Network, Genetics Society of Thailand, Bangkok 10330, Thailand
- Thailand Medical Genetics and Genomics Association (TMGGA), Bangkok 10510, Thailand
- Asia Pacific Society of Human Genetics (APSHG), Singapore 229899, Singapore
- Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
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8
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Chong SC, Cao Y, Fung ELW, Kleppe S, Gripp KW, Hertecant J, El-Hattab AW, Suleiman J, Clark G, von Allmen G, Rodziyevska O, Lewis RA, Rosenfeld JA, Dong J, Wang X, Miller MJ, Bi W, Liu P, Scaglia F. Expansion of the clinical and molecular spectrum of WWOX-related epileptic encephalopathy. Am J Med Genet A 2023; 191:776-785. [PMID: 36537114 DOI: 10.1002/ajmg.a.63074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 11/21/2022] [Accepted: 11/27/2022] [Indexed: 02/14/2023]
Abstract
WWOX biallelic loss-of-function pathogenic single nucleotide variants (SNVs) and copy number variants (CNVs) including exonic deletions and duplications cause WWOX-related epileptic encephalopathy (WOREE) syndrome. This disorder is characterized by refractory epilepsy, axial hypotonia, peripheral hypertonia, progressive microcephaly, and premature death. Here we report five patients with WWOX biallelic predicted null variants identified by exome sequencing (ES), genome sequencing (GS), and/or chromosomal microarray analysis (CMA). SNVs and intragenic deletions of one or more exons were commonly reported in WOREE syndrome patients which made the genetic diagnosis challenging and required a combination of different diagnostic technologies. These patients presented with severe, developmental and epileptic encephalopathy (DEE), and other cardinal features consistent with WOREE syndrome. This report expands the clinical phenotype associated with this condition, including failure to thrive in most patients and epilepsy that responded to a ketogenic diet in three patients. Dysmorphic features and abnormal prenatal findings were not commonly observed. Additionally, recurrent pancreatitis and sensorineural hearing loss each were observed in single patients. In summary, these phenotypic features broaden the clinical spectrum of WOREE syndrome.
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Affiliation(s)
- Shuk Ching Chong
- Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, China.,Joint BCM-CUHK Center of Medical Genetics, Chinese University of Hong Kong, Hong Kong, China
| | - Ye Cao
- Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, China.,Joint BCM-CUHK Center of Medical Genetics, Chinese University of Hong Kong, Hong Kong, China.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Obstetrics and Gynecology, The Chinese University of Hong Kong, Hong Kong, China
| | - Eva L W Fung
- Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, China
| | - Soledad Kleppe
- Unidad de Metabolismo, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Karen W Gripp
- Division of Medical Genetics, A. I. du Pont Hospital for Children/Nemours, Wilmington, Delaware, USA
| | - Jozef Hertecant
- Division of Genetic and Metabolic Disorders, Departments of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Gary Clark
- Neurology and Developmental Neuroscience, Baylor College of Medicine, Neurology Service, Texas Children's Hospital, Houston, Texas, USA
| | - Gretchen von Allmen
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School, Houston, Texas, USA
| | - Olga Rodziyevska
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School, Houston, Texas, USA
| | - Richard A Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Jie Dong
- Baylor Genetics, Houston, Texas, USA
| | | | - Xia Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - Marcus J Miller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - Fernando Scaglia
- Joint BCM-CUHK Center of Medical Genetics, Chinese University of Hong Kong, Hong Kong, China.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Obstetrics and Gynecology, The Chinese University of Hong Kong, Hong Kong, China.,Texas Children's Hospital, Houston, Texas, USA
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9
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Xie MJ, Cromie GA, Owens K, Timour MS, Tang M, Kutz JN, El-Hattab AW, McLaughlin RN, Dudley AM. Predicting the functional effect of compound heterozygous genotypes from large scale variant effect maps. bioRxiv 2023:2023.01.11.523651. [PMID: 36711904 PMCID: PMC9882023 DOI: 10.1101/2023.01.11.523651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Background Pathogenic variants in PHGDH, PSAT1 , and PSPH cause a set of rare, autosomal recessive diseases known as serine biosynthesis defects. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately in the form of infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, as childhood disease with intellectual disability. However, because L-serine supplementation, especially if started early, can ameliorate and in some cases even prevent symptoms, knowledge of pathogenic variants is highly actionable. Methods Recently, our laboratory established a yeast-based assay for human PSAT1 function. We have now applied it at scale to assay the functional impact of 1,914 SNV-accessible amino acid substitutions. In addition to assaying the functional impact of individual variants in yeast haploid cells, we can assay pairwise combinations of PSAT1 alleles that recapitulate human genotypes, including compound heterozygotes, in yeast diploids. Results Results of our assays of individual variants (in haploid yeast cells) agree well with clinical interpretations and protein structure-function relationships, supporting the use of our data as functional evidence under the ACMG interpretation guidelines. Results from our diploid assay successfully distinguish patient genotypes from those of healthy carriers and agree well with disease severity. Finally, we present a linear model that uses individual allele measurements (in haploid yeast cells) to accurately predict the biallelic function (in diploid yeast cells) of ~ 1.8 million allele combinations corresponding to potential human genotypes. Conclusions Taken together, our work provides an example of how large-scale functional assays in model systems can be powerfully applied to the study of a rare disease.
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10
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Al Ojaimi M, Salah A, El-Hattab AW. Mitochondrial Fission and Fusion: Molecular Mechanisms, Biological Functions, and Related Disorders. Membranes (Basel) 2022; 12:membranes12090893. [PMID: 36135912 PMCID: PMC9502208 DOI: 10.3390/membranes12090893] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/04/2022] [Accepted: 09/11/2022] [Indexed: 05/13/2023]
Abstract
Mitochondria are dynamic organelles that undergo fusion and fission. These active processes occur continuously and simultaneously and are mediated by nuclear-DNA-encoded proteins that act on mitochondrial membranes. The balance between fusion and fission determines the mitochondrial morphology and adapts it to the metabolic needs of the cells. Therefore, these two processes are crucial to optimize mitochondrial function and its bioenergetics abilities. Defects in mitochondrial proteins involved in fission and fusion due to pathogenic variants in the genes encoding them result in disruption of the equilibrium between fission and fusion, leading to a group of mitochondrial diseases termed disorders of mitochondrial dynamics. In this review, the molecular mechanisms and biological functions of mitochondrial fusion and fission are first discussed. Then, mitochondrial disorders caused by defects in fission and fusion are summarized, including disorders related to MFN2, MSTO1, OPA1, YME1L1, FBXL4, DNM1L, and MFF genes.
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Affiliation(s)
- Mode Al Ojaimi
- College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
| | - Azza Salah
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
| | - Ayman W. El-Hattab
- College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Pediatrics Department, University Hospital Sharjah, Sharjah 72772, United Arab Emirates
- Genetics and Metabolic Department, KidsHeart Medical Center, Abu Dhabi 505193, United Arab Emirates
- Correspondence: ; Tel.: +971-508875123
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11
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Abstract
WIPI (WD-repeat protein Interacting with PhosphoInositides) are important effectors in autophagy. These proteins bind phosphoinositides and recruit autophagy proteins. In mammals, there are four WIPI proteins: WIPI1, WIPI2, WIPI3 (WDR45B), and WIPI4 (WDR45). These proteins consist of a seven-bladed β-propeller structure. Recently, pathogenic variants in genes encoding these proteins have been recognized to cause human diseases with a predominant neurological phenotype. Defects in WIPI2 cause a disease characterized mainly by intellectual disability and variable other features while pathogenic variants in WDR45B and WDR45 have been recently reported to cause El-Hattab-Alkuraya syndrome and beta-propeller protein-associated neurodegeneration (BPAN), respectively. Whereas, there is no disease linked to WIPI1 yet, one study linked it neural tube defects (NTD). In this review, the role of WIPI proteins in autophagy is discussed first, then syndromes related to these proteins are summarized.
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Affiliation(s)
- Mohammed Almannai
- Genetics and Precision Medicine Department, King Abdullah Specialized Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- *Correspondence: Mohammed Almannai
| | - Dana Marafi
- Department of Pediatrics, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Department of Pediatrics, University Hospital Sharjah, Sharjah, United Arab Emirates
- Genetics and Metabolic Department, KidsHeart Medical Center, Abu Dhabi, United Arab Emirates
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12
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Almannai M, El-Hattab AW, Azamian MS, Ali M, Scaglia F. Mitochondrial DNA maintenance defects: potential therapeutic strategies. Mol Genet Metab 2022; 137:40-48. [PMID: 35914366 PMCID: PMC10401187 DOI: 10.1016/j.ymgme.2022.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/03/2022] [Accepted: 07/03/2022] [Indexed: 10/17/2022]
Abstract
Mitochondrial DNA (mtDNA) replication depends on the mitochondrial import of hundreds of nuclear encoded proteins that control the mitochondrial genome maintenance and integrity. Defects in these processes result in an expanding group of disorders called mtDNA maintenance defects that are characterized by mtDNA depletion and/or multiple mtDNA deletions with variable phenotypic manifestations. As it applies for mitochondrial disorders in general, current treatment options for mtDNA maintenance defects are limited. Lately, with the development of model organisms, improved understanding of the pathophysiology of these disorders, and a better knowledge of their natural history, the number of preclinical studies and existing and planned clinical trials has been increasing. In this review, we discuss recent preclinical studies and current and future clinical trials concerning potential therapeutic options for the different mtDNA maintenance defects.
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Affiliation(s)
- Mohammed Almannai
- Genetics and Precision Medicine Department (GPM), King Abdullah Specialized Children's Hospital (KASCH), King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Mahshid S Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - May Ali
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, Shatin, Hong Kong.
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13
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Ojaimi MA, Banimortada BJ, Othman A, Riedhammer KM, Almannai M, El-Hattab AW. Disorders of histone methylation: molecular basis and clinical syndromes. Clin Genet 2022; 102:169-181. [PMID: 35713103 DOI: 10.1111/cge.14181] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/01/2022]
Abstract
Epigenetic modifications of DNA and histone tails are essential for gene expression regulation. They play an essential role in neurodevelopment as nervous system development is a complex process requiring a dynamic pattern of gene expression. Histone methylation is one of the vital epigenetic regulators and mostly occurs on lysine residues of histones H3 and H4. Histone methylation is catalyzed by two sets of enzymes: histone lysine methyltransferases (KMTs) and histone lysine demethylases (KDMs). KMT2 enzymes form a distinct multi-subunit complex known as COMPASS to enhance their catalytic activity and diversify their biologic functions. Several neurodevelopmental syndromes result from defects of histone methylation which can be caused by deficiencies in histone methyltransferases and demethylases, loss of the histone methyltransferase activator TASP1, or derangements in COMPASS formation. In this review article, the molecular mechanism of histone methylation is discussed followed by summarizing clinical syndromes caused by monogenic defects in histone methylation.
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Affiliation(s)
- Mode Al Ojaimi
- College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | | | - Amna Othman
- Genetics and Genomic Medicine, Hamad Medical Corporation, Doha, Qatar
| | - Korbinian M Riedhammer
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Nephrology, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Mohammed Almannai
- Genetics and Precision Medicine Department, King Abdullah Specialized Children's Hospital, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Pediatrics Department, University Hospital Sharjah, Sharjah, United Arab Emirates.,Genetics and Metabolic Department, KidsHeart Medical Center, Abu Dhabi, United Arab Emirates
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14
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Almannai M, Salah A, El-Hattab AW. Mitochondrial Membranes and Mitochondrial Genome: Interactions and Clinical Syndromes. Membranes (Basel) 2022; 12:membranes12060625. [PMID: 35736332 PMCID: PMC9229594 DOI: 10.3390/membranes12060625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/06/2022] [Accepted: 06/14/2022] [Indexed: 11/16/2022]
Abstract
Mitochondria are surrounded by two membranes; the outer mitochondrial membrane and the inner mitochondrial membrane. They are unique organelles since they have their own DNA, the mitochondrial DNA (mtDNA), which is replicated continuously. Mitochondrial membranes have direct interaction with mtDNA and are therefore involved in organization of the mitochondrial genome. They also play essential roles in mitochondrial dynamics and the supply of nucleotides for mtDNA synthesis. In this review, we will discuss how the mitochondrial membranes interact with mtDNA and how this interaction is essential for mtDNA maintenance. We will review different mtDNA maintenance disorders that result from defects in this crucial interaction. Finally, we will review therapeutic approaches relevant to defects in mitochondrial membranes.
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Affiliation(s)
- Mohammed Almannai
- Genetics and Precision Medicine Department, King Abdullah Specialized Children Hospital, Riyadh P.O. Box 22490, Saudi Arabia
- Correspondence:
| | - Azza Salah
- Department of Pediatrics, University Hospital Sharjah, Sharjah P.O. Box 72772, United Arab Emirates;
| | - Ayman W. El-Hattab
- Department of Pediatrics, University Hospital Sharjah, Sharjah P.O. Box 72772, United Arab Emirates;
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates;
- Genetics and Metabolic Department, KidsHeart Medical Center, Abu Dhabi P.O. Box 505193, United Arab Emirates
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15
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Almannai M, Marafi D, Abdel-Salam GMH, Zaki MS, Duan R, Calame D, Herman I, Levesque FSHA, Elbendary HM, Hegazy I, Chung WK, Kavus H, Saeidi K, Maroofian R, AlHashim A, Al-Otaibi A, Madhi AA, Aboalseood HM, Alasmari A, Houlden H, Gleeson JG, Hunter JV, Posey JE, Lupski JR, El-Hattab AW. El-Hattab-Alkuraya syndrome caused by biallelic WDR45B pathogenic variants: further delineation of the phenotype and genotype. Clin Genet 2022; 101:530-540. [PMID: 35322404 PMCID: PMC9359317 DOI: 10.1111/cge.14132] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
Abstract
Homozygous pathogenic variants in WDR45B were first identified in six subjects from three unrelated families with global development delay, refractory seizures, spastic quadriplegia, and brain malformations. Since the initial report in 2018, no further cases have been described. In this report, we present 12 additional individuals from seven unrelated families and their clinical, radiological, and molecular findings. Six different variants in WDR45B were identified, five of which are novel. Microcephaly and global developmental delay were observed in all subjects, and seizures and spastic quadriplegia in most. Common findings on brain imaging include cerebral atrophy, ex-vacuo ventricular dilatation, brainstem volume loss, and symmetric under-opercularization. El-Hattab-Alkuraya syndrome is associated with a consistent phenotype characterized by early onset cerebral atrophy resulting in microcephaly, developmental delay, spastic quadriplegia, and seizures. The phenotype appears to be more severe among individuals with loss-of-function variants whereas those with missense variants were less severely affected suggesting a potential genotype-phenotype correlation in this disorder. A brain imaging pattern emerges which is consistent among individuals with loss-of-function variants and could potentially alert the neuroradiologists or clinician to consider WDR45B-related El-Hattab-Alkuraya syndrome. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mohammed Almannai
- Genetics and Precision Medicine department (GPM), King Abdullah Specialized Children's Hospital (KASCH), King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Pediatrics, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Ghada M H Abdel-Salam
- Clinical Genetics Department, Human Genetics and Genome Research Institute National Research Centre, Cairo, Egypt
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Institute National Research Centre, Cairo, Egypt.,Genetics Department, Armed Forces College of Medicine (AFCM), Cairo, Egypt
| | - Ruizhi Duan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Daniel Calame
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Isabella Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Felix S H A Levesque
- Division of medical genetics and metabolic, Department of Paediatrics, Jim Pattison Children's Hospital, University of Saskatchewan, Saskatoon, Canada
| | - Hasnaa M Elbendary
- Clinical Genetics Department, Human Genetics and Genome Research Institute National Research Centre, Cairo, Egypt
| | - Ibrahim Hegazy
- Clinical Genetics Department, Human Genetics and Genome Research Institute National Research Centre, Cairo, Egypt
| | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Haluk Kavus
- Departments of Pediatrics and Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Kolsoum Saeidi
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Reza Maroofian
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Aqeela AlHashim
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Al-Otaibi
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Asma Al Madhi
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Hager M Aboalseood
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Alasmari
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Henry Houlden
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Joseph G Gleeson
- Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, CA, USA
| | - Jill V Hunter
- Texas Children's Hospital, Houston, Texas, USA.,Department of Radiology, Baylor College of Medicine, Houston, Texas
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Genetics Clinics, University Hospital Sharjah, Sharjah, United Arab Emirates
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16
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Salah A, Almannai M, Ojaimi MA, Radefeldt M, Gulati N, Iqbal M, Alawbathani S, Al-Ali R, Beetz C, El-Hattab AW. A homozygous frame-shift variant in PROSER1 is associated with developmental delay, hypotonia, genitourinary malformations, and distinctive facial features. Clin Genet 2022; 101:565-570. [PMID: 35229282 DOI: 10.1111/cge.14126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/28/2022]
Abstract
We report four children from three related families who presented with a similar phenotype characterized by developmental delay, hypotonia, seizures, failure-to-thrive, strabismus, drooling, recurrent otitis media, hearing impairment, and genitourinary malformations. They also shared common facial features including arched eyebrows, prominent eyes, broad nasal bridge, low-hanging columella, open mouth, thick lower lip, protruding tongue, large low-set ears, and parietal bossing. Exome sequencing for affected individuals revealed a homozygous frame-shift variant, c.1833del; p.(Thr612Glnfs*22), in PROSER1 which encodes the proline and serine rich protein 1 (PROSER1). PROSER1 has recently been found to be part of the histone methyltransferases KMT2C/KMT2D complexes. PROSER1 stabilizes TET2, a member of TET family of DNA demethylases which is involved in recruiting the enhancer-associated KMT2C/KMT2D complexes and mediating DNA demethylation, activating gene expression. Therefore, PROSER1 may play vital and potentially general roles in gene regulation, consistent with the wide phenotypic spectrum observed in the individuals presented here. The consistent phenotype, the loss-of-function predicted from the frame-shift, the co-segregation of the phenotype in our large pedigree, the vital role of PROSER1 in gene regulation, and the association of related genes with neurodevelopmental disorders argue for the loss of PROSER1 to be the cause for a novel recognizable syndrome. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Azza Salah
- Pediatrics, University Hospital Sharjah, Sharjah, United Arab Emirates
| | - Mohammed Almannai
- Genetics and Precision Medicine Department, King Abdullah Specialized Children's Hospital, Riyadh, Saudi Arabia
| | - Mode Al Ojaimi
- College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | | | | | | | | | | | | | - Ayman W El-Hattab
- College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Clinical Genetics, University Hospital Sharjah, Sharjah, United Arab Emirates
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17
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Riedhammer KM, Burgemeister AL, Cantagrel V, Amiel J, Siquier-Pernet K, Boddaert N, Hertecant J, Kannouche PL, Pouvelle C, Htun S, Slavotinek AM, Beetz C, Diego-Alvarez D, Kampe K, Fleischer N, Awamleh Z, Weksberg R, Kopajtich R, Meitinger T, Suleiman J, El-Hattab AW. OUP accepted manuscript. Hum Mol Genet 2022; 31:3083-3094. [PMID: 35512351 PMCID: PMC9476618 DOI: 10.1093/hmg/ddac098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/04/2022] [Accepted: 04/23/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND TASP1 encodes an endopeptidase activating histone methyltransferases of the KMT2 family. Homozygous loss-of-function variants in TASP1 have recently been associated with Suleiman-El-Hattab syndrome. We report six individuals with Suleiman-El-Hattab syndrome and provide functional characterization of this novel histone modification disorder in a multi-omics approach. METHODS Chromosomal microarray/exome sequencing in all individuals. Western blotting from fibroblasts in two individuals. RNA sequencing and proteomics from fibroblasts in one individual. Methylome analysis from blood in two individuals. Knock-out of tasp1 orthologue in zebrafish and phenotyping. RESULTS All individuals had biallelic TASP1 loss-of-function variants and a phenotype including developmental delay, multiple congenital anomalies (including cardiovascular and posterior fossa malformations), a distinct facial appearance and happy demeanor. Western blot revealed absence of TASP1. RNA sequencing/proteomics showed HOX gene downregulation (HOXA4, HOXA7, HOXA1 and HOXB2) and dysregulation of transcription factor TFIIA. A distinct methylation profile intermediate between control and Kabuki syndrome (KMT2D) profiles could be produced. Zebrafish tasp1 knock-out revealed smaller head size and abnormal cranial cartilage formation in tasp1 crispants. CONCLUSION This work further delineates Suleiman-El-Hattab syndrome, a recognizable neurodevelopmental syndrome. Possible downstream mechanisms of TASP1 deficiency include perturbed HOX gene expression and dysregulated TFIIA complex. Methylation pattern suggests that Suleiman-El-Hattab syndrome can be categorized into the group of histone modification disorders including Wiedemann-Steiner and Kabuki syndrome.
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Affiliation(s)
- Korbinian M Riedhammer
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany
- Department of Nephrology, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | | | - Vincent Cantagrel
- Developmental Brain Disorders Laboratory, Université Paris Cité, Imagine Institute, INSERM UMR, 75015 Paris, France
| | - Jeanne Amiel
- Department of Genetics, AP-HP, Necker Enfants Malades Hospital, Université Paris Cité, Imagine Institute, 75015 Paris, France
| | - Karine Siquier-Pernet
- Developmental Brain Disorders Laboratory, Université Paris Cité, Imagine Institute, INSERM UMR, 75015 Paris, France
| | - Nathalie Boddaert
- Département de radiologie pédiatrique, INSERM UMR 1163 and INSERM U1000, AP-HP, Necker Enfants Malades Hospital, 75015 Paris, France
| | - Jozef Hertecant
- Division of Genetics and Metabolics, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
| | - Patricia L Kannouche
- CNRS UMR 9019, Université Paris-Saclay, Equipe labellisée Ligue contre le Cancer, Gustave Roussy, 94805 Villejuif, France
| | - Caroline Pouvelle
- CNRS UMR 9019, Université Paris-Saclay, Equipe labellisée Ligue contre le Cancer, Gustave Roussy, 94805 Villejuif, France
| | - Stephanie Htun
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anne M Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | | | | | - Zain Awamleh
- Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Rosanna Weksberg
- Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Molecular Genetics, Institute of Medical Sciences, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Robert Kopajtich
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ayman W El-Hattab
- To whom correspondence should be addressed at: College of Medicine, University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates. Tel: +971 508875123; Fax: +97137131044;
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Almannai M, El-Hattab AW. Nitric Oxide Deficiency in Mitochondrial Disorders: The Utility of Arginine and Citrulline. Front Mol Neurosci 2021; 14:682780. [PMID: 34421535 PMCID: PMC8374159 DOI: 10.3389/fnmol.2021.682780] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/21/2021] [Indexed: 11/21/2022] Open
Abstract
Mitochondrial diseases represent a growing list of clinically heterogeneous disorders that are associated with dysfunctional mitochondria and multisystemic manifestations. In spite of a better understanding of the underlying pathophysiological basis of mitochondrial disorders, treatment options remain limited. Over the past two decades, there is growing evidence that patients with mitochondrial disorders have nitric oxide (NO) deficiency due to the limited availability of NO substrates, arginine and citrulline; decreased activity of nitric oxide synthase (NOS); and NO sequestration. Studies evaluating the use of arginine in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) presenting with stroke-like episodes showed symptomatic improvement after acute administration as well as a reduction in the frequency and severity of stroke-like episodes following chronic use. Citrulline, another NO precursor, was shown through stable isotope studies to result in a greater increase in NO synthesis. Recent studies showed a positive response of arginine and citrulline in other mitochondrial disorders besides MELAS. Randomized-controlled studies with a larger number of patients are warranted to better understand the role of NO deficiency in mitochondrial disorders and the efficacy of NO precursors as treatment modalities in these disorders.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia.,College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Clinical Genetics, University Hospital Sharjah, Sharjah, United Arab Emirates
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19
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Abstract
Metabolic diseases should always be considered when evaluating children presenting with seizures. This is because many metabolic disorders are potentially treatable and seizure control can be achieved when these diseases are appropriately treated. Seizures caused by underlying metabolic diseases (metabolic seizures) should be particularly considered in unexplained neonatal seizures, refractory seizures, seizures related to fasting or food intake, seizures associated with other systemic or neurologic features, parental consanguinity, and family history of epilepsy. Metabolic seizures can be caused by various amino acids metabolic disorders, disorders of energy metabolism, cofactor-related metabolic diseases, purine and pyrimidine metabolic diseases, congenital disorders of glycosylation, and lysosomal and peroxisomal disorders. Diagnosing metabolic seizures without delay is essential because the immediate initiation of appropriate therapy for many metabolic diseases can prevent or minimize complications.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Rabah A Al Mahmoud
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Department of Pediatrics, University Hospital Sharjah, Sharjah, United Arab Emirates
| | - Mohammed Mekki
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Department of Pediatrics, Al Qassimi Women's and Children's Hospital, Sharjah, United Arab Emirates
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Clinical Genetics, University Hospital Sharjah, Sharjah, United Arab Emirates
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20
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Arora V, Khan S, W. El-Hattab A, Dua Puri R, Rocha ME, Merdzanic R, Paknia O, Beetz C, Rolfs A, Bertoli-Avella AM, Bauer P, Verma IC. Biallelic Pathogenic GFRA1 Variants Cause Autosomal Recessive Bilateral Renal Agenesis. J Am Soc Nephrol 2021; 32:223-228. [PMID: 33020172 PMCID: PMC7894660 DOI: 10.1681/asn.2020040478] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/30/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Congenital anomalies of the kidney and urinary tract (CAKUT) are one of the most common malformations identified in the fetal stage. Bilateral renal agenesis (BRA) represents the most severe and fatal form of CAKUT. Only three genes have been confirmed to have a causal role in humans (ITGA8, GREB1L, and FGF20). METHODS Genome sequencing within a diagnostic setting and combined data repository analysis identified a novel gene. RESULTS Two patients presented with BRA, detected during the prenatal period, without additional recognizable malformations. They had parental consanguinity and similarly affected, deceased siblings, suggesting autosomal recessive inheritance. Evaluation of homozygous regions in patient 1 identified a novel, nonsense variant in GFRA1 (NM_001348097.1:c.676C>T, p.[Arg226*]). We identified 184 patients in our repository with renal agenesis and analyzed their exome/genome data. Of these 184 samples, 36 were from patients who presented with isolated renal agenesis. Two of them had loss-of-function variants in GFRA1. The second patient was homozygous for a frameshift variant (NM_001348097.1:c.1294delA, p.[Thr432Profs*13]). The GFRA1 gene encodes a receptor on the Wolffian duct that regulates ureteric bud outgrowth in the development of a functional renal system, and has a putative role in the pathogenesis of Hirschsprung disease. CONCLUSIONS These findings strongly support the causal role of GFRA1-inactivating variants for an autosomal recessive, nonsyndromic form of BRA. This knowledge will enable early genetic diagnosis and better genetic counseling for families with BRA.
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Affiliation(s)
- Veronica Arora
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | | | - Ayman W. El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | | | | | | | | | - Arndt Rolfs
- CENTOGENE GmbH, Rostock, Germany
- University of Rostock, Rostock, Germany
| | | | | | - Ishwar C. Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
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21
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Abstract
Mitochondrial disorders comprise a molecular and clinically diverse group of diseases that are associated with mitochondrial dysfunction leading to multi-organ disease. With recent advances in molecular technologies, the understanding of the pathomechanisms of a growing list of mitochondrial disorders has been greatly expanded. However, the therapeutic approaches for mitochondrial disorders have lagged behind with treatment options limited mainly to symptom specific therapies and supportive measures. There is an increasing number of clinical trials in mitochondrial disorders aiming for more specific and effective therapies. This review will cover different treatment modalities currently used in mitochondrial disorders, focusing on recent and ongoing clinical trials.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - May Ali
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Claudia Soler-Alfonso
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, Shatin, Hong Kong.
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22
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Segal MM, George R, Waltman P, El-Hattab AW, James KN, Stanley V, Gleeson J. Clinician-centric diagnosis of rare genetic diseases: performance of a gene pertinence metric in decision support for clinicians. Orphanet J Rare Dis 2020; 15:191. [PMID: 32698834 PMCID: PMC7374885 DOI: 10.1186/s13023-020-01461-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/07/2020] [Indexed: 12/30/2022] Open
Abstract
Background In diagnosis of rare genetic diseases we face a decision as to the degree to which the sequencing lab offers one or more diagnoses based on clinical input provided by the clinician, or the clinician reaches a diagnosis based on the complete set of variants provided by the lab. We tested a software approach to assist the clinician in making the diagnosis based on clinical findings and an annotated genomic variant table, using cases already solved using less automated processes. Results For the 81 cases studied (involving 216 individuals), 70 had genetic abnormalities with phenotypes previously described in the literature, and 11 were not described in the literature at the time of analysis (“discovery genes”). These included cases beyond a trio, including ones with different variants in the same gene. In 100% of cases the abnormality was recognized. Of the 70, the abnormality was ranked #1 in 94% of cases, with an average rank 1.1 for all cases. Large CNVs could be analyzed in an integrated analysis, performed in 24 of the cases. The process is rapid enough to allow for periodic reanalysis of unsolved cases. Conclusions A clinician-friendly environment for clinical correlation can be provided to clinicians who are best positioned to have the clinical information needed for this interpretation.
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Affiliation(s)
| | - Renee George
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, USA
| | - Peter Waltman
- Rockefeller University, New York, NY, USA.,current address Department of Systems Biology, Columbia University, New York, NY, USA
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Kiely N James
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, USA
| | - Valentina Stanley
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, USA
| | - Joseph Gleeson
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, USA
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23
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Marafi D, Mitani T, Isikay S, Hertecant J, Almannai M, Manickam K, Abou Jamra R, El-Hattab AW, Rajah J, Fatih JM, Du H, Karaca E, Bayram Y, Punetha J, Rosenfeld JA, Jhangiani SN, Boerwinkle E, Akdemir ZC, Erdin S, Hunter JV, Gibbs RA, Pehlivan D, Posey JE, Lupski JR. Biallelic GRM7 variants cause epilepsy, microcephaly, and cerebral atrophy. Ann Clin Transl Neurol 2020; 7:610-627. [PMID: 32286009 PMCID: PMC7261753 DOI: 10.1002/acn3.51003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 01/29/2023] Open
Abstract
Objective Defects in ion channels and neurotransmitter receptors are implicated in developmental and epileptic encephalopathy (DEE). Metabotropic glutamate receptor 7 (mGluR7), encoded by GRM7, is a presynaptic G‐protein‐coupled glutamate receptor critical for synaptic transmission. We previously proposed GRM7 as a candidate disease gene in two families with neurodevelopmental disorders (NDDs). One additional family has been published since. Here, we describe three additional families with GRM7 biallelic variants and deeply characterize the associated clinical neurological and electrophysiological phenotype and molecular data in 11 affected individuals from six unrelated families. Methods Exome sequencing and family‐based rare variant analyses on a cohort of 220 consanguineous families with NDDs revealed three families with GRM7 biallelic variants; three additional families were identified through literature search and collaboration with a clinical molecular laboratory. Results We compared the observed clinical features and variants of 11 affected individuals from the six unrelated families. Identified novel deleterious variants included two homozygous missense variants (c.2671G>A:p.Glu891Lys and c.1973G>A:p.Arg685Gln) and one homozygous stop‐gain variant (c.1975C>T:p.Arg659Ter). Developmental delay, neonatal‐ or infantile‐onset epilepsy, and microcephaly were universal. Three individuals had hypothalamic–pituitary–axis dysfunction without pituitary structural abnormality. Neuroimaging showed cerebral atrophy and hypomyelination in a majority of cases. Two siblings demonstrated progressive loss of myelination by 2 years in both and an acquired microcephaly pattern in one. Five individuals died in early or late childhood. Conclusion Detailed clinical characterization of 11 individuals from six unrelated families demonstrates that rare biallelic GRM7 pathogenic variants can cause DEEs, microcephaly, hypomyelination, and cerebral atrophy.
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Affiliation(s)
- Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Department of Pediatrics, Faculty of Medicine, Kuwait University, P.O. Box 24923, 13110, Safat, Kuwait
| | - Tadahiro Mitani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Sedat Isikay
- Department of Physiotherapy and Rehabilitation, School of Health Sciences, Hasan Kalyoncu University, Gaziantep, 27000, Turkey
| | - Jozef Hertecant
- Pediatric Metabolic and Genetics Division, Tawam Hospital, Al Ain, Abu Dhabi, United Arab Emirates
| | - Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, 11525, Saudi Arabia
| | - Kandamurugu Manickam
- Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, 04103, Leipzig, Germany
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Jaishen Rajah
- Sheikh Khalifa Medical City (SKMC), P.O. Box: 51900, Abu Dhabi, United Arab Emirates
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Ender Karaca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Yavuz Bayram
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jaya Punetha
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030
| | - Eric Boerwinkle
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030.,Human Genetics Center, University of Texas Health Science Center at Houston, Houston, Texas
| | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Serkan Erdin
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Jill V Hunter
- Texas Children's Hospital, Houston, Texas, 77030.,Department of Radiology, Baylor College of Medicine, Houston, Texas, 77030
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Texas Children's Hospital, Houston, Texas, 77030.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, 77030
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030.,Texas Children's Hospital, Houston, Texas, 77030.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, 77030
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24
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Ballout RA, Dickerson C, Wick MJ, Al-Sweel N, Openshaw AS, Srivastava S, Swanson LC, Bramswig NC, Kuechler A, Hong B, Fleming LR, Curry K, Robertson SP, Andersen EF, El-Hattab AW. Int22h1/Int22h2-mediated Xq28 duplication syndrome: de novo duplications, prenatal diagnoses, and additional phenotypic features. Hum Mutat 2020; 41:1238-1249. [PMID: 32112660 DOI: 10.1002/humu.24009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 12/11/2022]
Abstract
Int22h1/Int22h2-mediated Xq28 duplication syndrome is a relatively new X-linked intellectual disability syndrome, arising from duplications of the subregion flanked by intron 22 homologous regions 1 and 2 on the q arm of chromosome X. Its primary manifestations include variable cognitive deficits, distinct facial dysmorphia, and neurobehavioral abnormalities that mainly include hyperactivity, irritability, and autistic behavior. Affected males are hemizygous for the duplication, which explains their often more severe manifestations compared with heterozygous females. In this report, we describe the cases of nine individuals recently identified having the syndrome, highlighting unique and previously unreported findings of this syndrome. Specifically, we report for the first time in this syndrome, two cases with de novo duplications, three receiving prenatal diagnosis with the syndrome, and three others having atypical versions of the duplication. Among the latter, one proband has a shortened version spanning only the centromeric half of the typical duplication, while the other two cases have a nearly identical length duplication as the classical duplication, with the exception that their duplication's breakpoints are telomerically shifted by about 0.2 Mb. Finally, we shed light on two new manifestations in this syndrome, vertebral anomalies and multiple malignancies, which possibly expand the phenotypic spectrum of the syndrome.
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Affiliation(s)
- Rami A Ballout
- Lipoprotein Metabolism Section, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.,Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Cheryl Dickerson
- WakeMed Physician Practices, Maternal-Fetal Medicine, Raleigh, North Carolina
| | - Myra J Wick
- Departments of Obstetrics and Gynecology and Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Najla Al-Sweel
- Department of Pathology, University of Utah, Salt Lake City, Utah.,ARUP Laboratories, Cytogenetics and Genomic Microarray, Salt Lake City, Utah
| | - Amanda S Openshaw
- ARUP Laboratories, Cytogenetics and Genomic Microarray, Salt Lake City, Utah
| | | | - Lindsay C Swanson
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Nuria C Bramswig
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Alma Kuechler
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Bo Hong
- Department of Pathology, University of Utah, Salt Lake City, Utah.,ARUP Laboratories, Cytogenetics and Genomic Microarray, Salt Lake City, Utah
| | - Leah R Fleming
- St. Luke's Children's Genetics and Metabolic Clinic, Boise, Idaho
| | - Kathryn Curry
- St. Luke's Children's Genetics and Metabolic Clinic, Boise, Idaho
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Erica F Andersen
- Department of Pathology, University of Utah, Salt Lake City, Utah.,ARUP Laboratories, Cytogenetics and Genomic Microarray, Salt Lake City, Utah
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE
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25
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Al Jasmi F, Al Zaabi N, Al-Thihli K, Al Teneiji AM, Hertecant J, El-Hattab AW. Endothelial Dysfunction and the Effect of Arginine and Citrulline Supplementation in Children and Adolescents With Mitochondrial Diseases. J Cent Nerv Syst Dis 2020; 12:1179573520909377. [PMID: 32165851 PMCID: PMC7050027 DOI: 10.1177/1179573520909377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/01/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND In addition to the reduced energy production, characteristic of mitochondrial disorders, nitric oxide (NO) deficiency can occur as well. The NO produced by vascular endothelial cells relaxes vascular smooth muscles, resulting in vasodilation that maintains the patency of small blood vessels and promotes blood flow through microvasculature. Endothelial dysfunction due to inability of vascular endothelium to generate enough NO to maintain adequate vasodilation can result in decreased perfusion in the microvasculature of various tissues, contributing to many complications seen in individuals with mitochondrial diseases. The amino acids arginine and citrulline are NO precursors: increasing their concentrations could potentially restore NO production. METHODS In this study, we assessed endothelial dysfunction in children and adolescents with mitochondrial diseases. We also investigated the effect of arginine and citrulline supplementation on endothelial dysfunction in these individuals. We used peripheral arterial tonometry to measure the reactive hyperemic index (RHI), which is low when there is endothelial dysfunction. RESULTS The results demonstrated low RHI in individuals with mitochondrial diseases, indicating endothelial dysfunction. RHI increased with arginine or citrulline supplementation suggesting that supplementation with NO precursors can improve endothelial dysfunction by enhancing NO production. CONCLUSIONS This study is the first one to use peripheral arterial tonometry methodology in mitochondrial diseases. The results of this study provide evidence for endothelial dysfunction in mitochondrial diseases and demonstrate that arginine or citrulline supplementation can alleviate the endothelial dysfunction, providing more evidence for the potential therapeutic utility of these amino acids in mitochondrial diseases.
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Affiliation(s)
- Fatma Al Jasmi
- Division of Clinical Genetic and Metabolic Disorders, Tawam Hospital, Al-Ain, United Arab Emirates
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Nuha Al Zaabi
- Division of Clinical Genetic and Metabolic Disorders, Tawam Hospital, Al-Ain, United Arab Emirates
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Khalid Al-Thihli
- Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Oman
| | - Amal M Al Teneiji
- Genetic and Metabolic Division, Pediatrics Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Jozef Hertecant
- Division of Clinical Genetic and Metabolic Disorders, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
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26
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Beetz C, Ameziane N, Kdissa A, Karageorgou V, Bauer P, Suleiman J, Sutton VR, El-Hattab AW. VPS26C homozygous nonsense variant in two cousins with neurodevelopmental deficits, growth failure, skeletal abnormalities, and distinctive facial features. Clin Genet 2019; 97:644-648. [PMID: 31845315 DOI: 10.1111/cge.13690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 11/26/2022]
Abstract
In this report, we describe two cousins with cognitive impairment, growth failure, skeletal abnormalities, and distinctive facial features. Genome sequencing failed to identify variants in known disease-associated genes explaining the phenotype. Extended comprehensive analysis of the two affected cousins' genomes, however, revealed that both share the homozygous nonsense variant c.178G>T (p.Glu60*) in the VPS26C gene. This gene encodes VPS26C, a member of the retriever integral membrane protein recycling pathway. The potential vital biological role of VPS26C, the nature of the variant which is predicted to result in loss-of-function, expression studies revealing significant reduction in the mutant transcript, and the co-segregation of the homozygous variant with the phenotype in two affected individuals all support that VPS26C is a novel gene associated with a previously unrecognized syndrome characterized by neurodevelopmental deficits, growth failure, skeletal abnormalities, and distinctive facial features.
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Affiliation(s)
| | | | | | | | | | - Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
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Abstract
Carnitine plays essential roles in intermediary metabolism. In non-vegetarians, most of carnitine sources (~75%) are obtained from diet whereas endogenous synthesis accounts for around 25%. Renal carnitine reabsorption along with dietary intake and endogenous production maintain carnitine homeostasis. The precursors for carnitine biosynthesis are lysine and methionine. The biosynthetic pathway involves four enzymes: 6-N-trimethyllysine dioxygenase (TMLD), 3-hydroxy-6-N-trimethyllysine aldolase (HTMLA), 4-N-trimethylaminobutyraldehyde dehydrogenase (TMABADH), and γ-butyrobetaine dioxygenase (BBD). OCTN2 (organic cation/carnitine transporter novel type 2) transports carnitine into the cells. One of the major functions of carnitine is shuttling long-chain fatty acids across the mitochondrial membrane from the cytosol into the mitochondrial matrix for β-oxidation. This transport is achieved by mitochondrial carnitine–acylcarnitine cycle, which consists of three enzymes: carnitine palmitoyltransferase I (CPT I), carnitine-acylcarnitine translocase (CACT), and carnitine palmitoyltransferase II (CPT II). Carnitine inborn errors of metabolism could result from defects in carnitine biosynthesis, carnitine transport, or mitochondrial carnitine–acylcarnitine cycle. The presentation of these disorders is variable but common findings include hypoketotic hypoglycemia, cardio(myopathy), and liver disease. In this review, the metabolism and homeostasis of carnitine are discussed. Then we present details of different inborn errors of carnitine metabolism, including clinical presentation, diagnosis, and treatment options. At the end, we discuss some of the causes of secondary carnitine deficiency.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh 11525, Saudi Arabia.
| | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh 11426, Saudi Arabia.
- King Abdullah International Medical Research Center (KAIMRC), Riyadh 11426, Saudi Arabia.
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia.
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, UAE.
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28
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Suleiman J, Riedhammer KM, Jicinsky T, Mundt M, Werner L, Gusic M, Burgemeister AL, Alsaif HS, Abdulrahim M, Moghrabi NN, Nicolas-Jilwan M, AlSayed M, Bi W, Sampath S, Alkuraya FS, El-Hattab AW. Homozygous loss-of-function variants of TASP1, a gene encoding an activator of the histone methyltransferases KMT2A and KMT2D, cause a syndrome of developmental delay, happy demeanor, distinctive facial features, and congenital anomalies. Hum Mutat 2019; 40:1985-1992. [PMID: 31209944 DOI: 10.1002/humu.23844] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/31/2019] [Accepted: 06/09/2019] [Indexed: 12/20/2022]
Abstract
We report four unrelated children with homozygous loss-of-function variants in TASP1 and an overlapping phenotype comprising developmental delay with hypotonia and microcephaly, feeding difficulties with failure-to-thrive, recurrent respiratory infections, cardiovascular malformations, cryptorchidism, happy demeanor, and distinctive facial features. Two children had a homozygous founder deletion encompassing exons 5-11 of TASP1, the third had a homozygous missense variant, c.701 C>T (p.Thr234Met), affecting the active site of the encoded enzyme, and the fourth had a homozygous nonsense variant, c.199 C>T (p.Arg67*). TASP1 encodes taspase 1 (TASP1), which is responsible for cleaving, thus activating, the lysine methyltransferases KMT2A and KMT2D, which are essential for histone methylation and transcription regulation. The consistency of the phenotype, the critical biological function of TASP1, the deleterious nature of the TASP1 variants, and the overlapping features with Wiedemann-Steiner and Kabuki syndromes respectively caused by pathogenic variants in KMT2A and KMT2D all support that TASP1 is a disease-related gene.
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Affiliation(s)
- Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Korbinian M Riedhammer
- Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany.,Department of Nephrology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | | | | | | | - Mirjana Gusic
- Institute of Human Genetics, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany
| | | | - Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maha Abdulrahim
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nabil N Moghrabi
- Molecular Diagnostic Laboratory, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Manal Nicolas-Jilwan
- Division of Neuroradiology, Department of Radiology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Moeenaldeen AlSayed
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics, Houston, Texas
| | | | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Genetics Clinics, KidsHeart Medical Center, Abu Dhabi, United Arab Emirates
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29
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Almannai M, Felemban R, Saleh MA, Faqeih EA, Alasmari A, AlHashem A, Mohamed S, Sunbul R, Al-Murshedi F, AlThihli K, Eyaid W, Ali R, Ben-Omran T, Blau N, El-Hattab AW, Alfadhel M. 6-Pyruvoyltetrahydropterin Synthase Deficiency: Review and Report of 28 Arab Subjects. Pediatr Neurol 2019; 96:40-47. [PMID: 30926181 DOI: 10.1016/j.pediatrneurol.2019.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/03/2019] [Accepted: 02/10/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND Tetrahydrobiopterin is an essential cofactor for the hydroxylation of aromatic amino acids phenylalanine, tyrosine, and tryptophan. Therefore, tetrahydrobiopterin deficiency results in hyperphenylalaninemia as well as dopamine and serotonin depletion in the central nervous system. The enzyme 6-pyruvoyltetrahydropterin synthase catalyzes the second step of de novo synthesis of tetrahydrobiopterin, and its deficiency is the most frequent cause of tetrahydrobiopterin metabolism disorders. METHOD We conducted a retrospective chart review of 28 subjects from 24 families with molecularly confirmed 6-pyruvoyltetrahydropterin synthase deficiency from six centers in three Arab countries. We reviewed clinical, biochemical, and molecular data. We also reviewed previously published cohorts of subjects with 6-pyruvoyltetrahydropterin synthase deficiency. RESULTS Similar to previous observations, we show that early treatment (less than two months) is associated with better outcome. We identify eight PTS variants in 24 independent families. The most common variant is (c.238A>G; p.M80V) with an allele count of 33%. We also identify one novel variant (c.2T>G; p.?). CONCLUSION The deficiency of 6-pyruvoyltetrahydropterin synthase is relatively common in the Arab population and should be considered in individuals with hyperphenylalaninemia. More natural history studies with comprehensive biochemical and molecular genetics data are needed for a robust base for the development of future therapy.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Rana Felemban
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Mohammed A Saleh
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Eissa A Faqeih
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Alasmari
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Amal AlHashem
- Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Sarar Mohamed
- Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia
| | - Rawda Sunbul
- Pediatrics Medical Genetic Unit (PMGU), Pediatrics Department, Qatif Central Hospital, Qatif, Saudi Arabia
| | - Fathiya Al-Murshedi
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Khalid AlThihli
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Wafaa Eyaid
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Rehab Ali
- Clinical and Metabolic Genetics Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Tawfeg Ben-Omran
- Clinical and Metabolic Genetics Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Nenad Blau
- Dietmar-Hopp-Metabolic Center, University Children's Hospital, Heidelberg, Germany; Division of Metabolism, University Children's Hospital Zurich, Switzerland
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates; Genetics Clinics, KidsHeart Medical Center, Dubai, United Arab Emirates
| | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia; King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia; College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
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30
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Mu W, Schiess N, Orthmann-Murphy JL, El-Hattab AW. The utility of whole exome sequencing in diagnosing neurological disorders in adults from a highly consanguineous population. J Neurogenet 2019; 33:21-26. [PMID: 30724636 DOI: 10.1080/01677063.2018.1555249] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is increasing evidence that whole exome sequencing (WES) has a high diagnostic yield and is cost-efficient for individuals with neurological phenotypes. However, there is limited data on the use of WES in non-Western populations, including populations with a high rate of consanguinity. Retrospective chart review was performed on 24 adults with undiagnosed neurological symptoms evaluated in genetics and neurology clinics in a tertiary care facility on the Arabian Peninsula, and had WES between 2014 and 2016. Definitive diagnoses were made in 13/24 (54%) of cases. Of these, 5/13 (38%) revealed novel pathogenic variants. Of the known 19/24 (79%) consanguineous cases, diagnostic rate was slightly higher, 11/19 (58%) as compared to 2/5 (40%) among non-consanguineous cases. Autosomal recessive disorders comprised 10/13 (77%) of molecular diagnoses, all found to be due to homozygous pathogenic variants among consanguineous cases. WES in this cohort of adults with neurological symptoms had a high diagnostic rate likely due to high consanguinity rates in this population, as evidenced by the high diagnostic rate of homozygous pathogenic variants.
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Affiliation(s)
- Weiyi Mu
- a Institute of Genetic Medicine , Johns Hopkins University , Baltimore , MD , USA
| | - Nicoline Schiess
- b Department of Neurology , Johns Hopkins University , Baltimore , MD , USA
| | - Jennifer L Orthmann-Murphy
- b Department of Neurology , Johns Hopkins University , Baltimore , MD , USA.,c Department of Neurology , Hospital of the University of Pennsylvania , Philadelphia , PA , USA
| | - Ayman W El-Hattab
- d Division of Clinical Genetics and Metabolic Disorder , Tawam Hospital , Al-Ain , United Arab Emirates
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31
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Ballout RA, Al Alam C, Bonnen PE, Huemer M, El-Hattab AW, Shbarou R. FBXL4-Related Mitochondrial DNA Depletion Syndrome 13 (MTDPS13): A Case Report With a Comprehensive Mutation Review. Front Genet 2019; 10:39. [PMID: 30804983 PMCID: PMC6370620 DOI: 10.3389/fgene.2019.00039] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 01/18/2019] [Indexed: 01/28/2023] Open
Abstract
Mitochondrial DNA depletion syndromes (MTDPS) are a group of rare genetic disorders caused by defects in multiple genes involved in mitochondrial DNA (mtDNA) maintenance. Among those, FBXL4 mutations result in the encephalomyopathic mtDNA depletion syndrome 13 (MTDPS13; OMIM #615471), which commonly presents as a combination of failure to thrive, neurodevelopmental delays, encephalopathy, hypotonia, and persistent lactic acidosis. We report here the case of a Lebanese infant presenting to us with profound neurodevelopmental delays, generalized hypotonia, facial dysmorphic features, and extreme emaciation. Whole-exome sequencing (WES) showed the girl as having MTDPS13 with an underlying FBXL4 missense mutation that has been previously reported only twice in unrelated individuals (c.1303C > T). Comprehensive literature search marked our patient as being the 94th case of MTDPS13 reported to date worldwide, and the first from Lebanon. We include at the end of this report a comprehensive mutation review table of all the pathological FBXL4 mutations reported in the literature, using it to highlight, for the first time, a possible founder effect of Arab origins to the disorder, being most prevalent in patients of Arab descent as shown in our mutation table. Finally, we provide a direct comparison of the disorder's clinical manifestations across two unrelated patients harboring the same disease-causing mutation as our patient, emphasizing the remarkable variability in genotype-to-phenotype correlation characteristic of the disease.
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Affiliation(s)
- Rami A Ballout
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Chadi Al Alam
- Division of Pediatric Neurology, Department of Pediatrics, American University of Beirut Medical Center, Beirut, Lebanon
| | - Penelope E Bonnen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Martina Huemer
- Department of Pediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria.,Division of Metabolism, University Children's Hospital Zürich, Zurich, Switzerland
| | - Ayman W El-Hattab
- Genetics Clinic, KidsHeart Medical Center, Dubai, United Arab Emirates
| | - Rolla Shbarou
- Division of Pediatric Neurology, Department of Pediatrics, American University of Beirut Medical Center, Beirut, Lebanon
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32
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Affiliation(s)
- Jehan Suleiman
- Division of Pediatric Neurology, Tawam Hospital, Al Ain, United Arab Emirates
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Tawam Hospital, Al-Ain, United Arab Emirates.
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33
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El-Hattab AW, Suleiman J, Almannai M, Scaglia F. Mitochondrial dynamics: Biological roles, molecular machinery, and related diseases. Mol Genet Metab 2018; 125:315-321. [PMID: 30361041 DOI: 10.1016/j.ymgme.2018.10.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/15/2018] [Indexed: 01/09/2023]
Abstract
Mitochondria are dynamic organelles that undergo fusion, fission, movement, and mitophagy. These processes are essential to maintain the normal mitochondrial morphology, distribution, and function. Mitochondrial fusion allows the exchange of intramitochondrial material, whereas the fission process is required to replicate the mitochondria during cell division, facilitate the transport and distribution of mitochondria, and allow the isolation of damaged organelles. Mitochondrial mobility is essential for mitochondrial distribution depending on the cellular metabolic demands. Mitophagy is needed for the elimination of dysfunctional and damaged mitochondria to maintain a healthy mitochondrial population. The mitochondrial dynamic processes are mediated by a number of nuclear-encoded proteins that function in mitochondrial transport, fusion, fission, and mitophagy. Disorders of mitochondrial dynamics are caused by pathogenic variants in the genes encoding these proteins. These diseases have a high clinical variability, and range in severity from isolated optic atrophy to lethal encephalopathy. These disorders include defects in mitochondrial fusion (caused by pathogenic variants in MFN2, OPA1, YME1L1, MSTO1, and FBXL4), mitochondrial fission (caused by pathogenic variants in DNM1L and MFF), and mitochondrial autophagy (caused by pathogenic variants in PINK1 and PRKN). In this review, the molecular machinery and biological roles of mitochondrial dynamic processes are discussed. Subsequently, the currently known diseases related to mitochondrial dynamic defects are presented.
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Affiliation(s)
- Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Jehan Suleiman
- Division of Neurology, Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates
| | - Mohammed Almannai
- Medical Genetics Division, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, ShaTin, Hong Kong Special Administrative Region.
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34
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Chan TK, Alkaabi MK, ElBarky AM, El-Hattab AW. LOXL3 novel mutation causing a rare form of autosomal recessive Stickler syndrome. Clin Genet 2018; 95:325-328. [PMID: 30362103 DOI: 10.1111/cge.13465] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 11/30/2022]
Abstract
Stickler syndrome is a collagenopathy that is typically inherited as autosomal dominant disease caused by monoallelic mutations in COL2A1, COL11A2, and COL11A1. Rarely, biallelic mutations in COL9A1, COL9A2, and COL9A3 cause an autosomal recessive Stickler syndrome. One previous report described two siblings with Stickler syndrome and a homozygous mutation in LOXL3, suggesting that biallelic mutations in LOXL3 can also cause autosomal recessive Stickler syndrome. LOXL3 is a member of the lysyl oxidase family of genes which encode enzymes oxidizing the side chain of peptidyl lysine permitting the covalent crosslinking of collagen and elastin chains. Therefore, LOXL3 deficiency is expected to result in collagen defect. Furthermore, Loxl3 deficient mouse model demonstrated features overlapping with Stickler syndrome. In this report, we describe a child and his father who had clinical features consistent with Stickler syndrome and found to have a homozygous novel mutation c.1036C>T (p.Arg346Trp) in LOXL3. This report not only supports that biallelic LOXL3 mutations cause autosomal recessive Stickler syndrome, but also further delineates the phenotype associated with LOXL3 mutations. In addition, the family described here shows an interesting example for pseudodominance, which can be observed in recessive diseases when one parent is affected and the other is heterozygous carrier.
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Affiliation(s)
- Tin K Chan
- Ophthalmology Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates.,Department of Ophthalmology, Princess Alexandra Eye Pavilion, Edinburgh, U.K
| | - Mohammed K Alkaabi
- Ophthalmology Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | - Ahmed M ElBarky
- Ophthalmology Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates.,Benha Faculty of Medicine, Benha University, Benha, Egypt
| | - Ayman W El-Hattab
- Division of Genetic and Metabolic Disorders, Tawam Hospital, Al Ain, United Arab Emirates
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35
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Almannai M, Wang J, Dai H, El-Hattab AW, Faqeih EA, Saleh MA, Al Asmari A, Alwadei AH, Aljadhai YI, AlHashem A, Tabarki B, Lines MA, Grange DK, Benini R, Alsaman AS, Mahmoud A, Katsonis P, Lichtarge O, Wong LJC. FARS2 deficiency; new cases, review of clinical, biochemical, and molecular spectra, and variants interpretation based on structural, functional, and evolutionary significance. Mol Genet Metab 2018; 125:281-291. [PMID: 30177229 DOI: 10.1016/j.ymgme.2018.07.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 02/07/2023]
Abstract
An increasing number of mitochondrial diseases are found to be caused by pathogenic variants in nuclear encoded mitochondrial aminoacyl-tRNA synthetases. FARS2 encodes mitochondrial phenylalanyl-tRNA synthetase (mtPheRS) which transfers phenylalanine to its cognate tRNA in mitochondria. Since the first case was reported in 2012, a total of 21 subjects with FARS2 deficiency have been reported to date with a spectrum of disease severity that falls between two phenotypes; early onset epileptic encephalopathy and a less severe phenotype characterized by spastic paraplegia. In this report, we present an additional 15 individuals from 12 families who are mostly Arabs homozygous for the pathogenic variant Y144C, which is associated with the more severe early onset phenotype. The total number of unique pathogenic FARS2 variants known to date is 21 including three different partial gene deletions reported in four individuals. Except for the large deletions, all variants but two (one in-frame deletion of one amino acid and one splice-site variant) are missense. All large deletions and the single splice-site variant are in trans with a missense variant. This suggests that complete loss of function may be incompatible with life. In this report, we also review structural, functional, and evolutionary significance of select FARS2 pathogenic variants reported here.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Julia Wang
- Medical Scientist Training Program and Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatric Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Eissa A Faqeih
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Mohammed A Saleh
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Al Asmari
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali H Alwadei
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Yaser I Aljadhai
- Department of Neuroimaging and Intervention, Medical Imaging Administration, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Amal AlHashem
- Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Divisions of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Matthew A Lines
- Division of Metabolics and Newborn Screening, Children's Hospital of Eastern Ontario, Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Dorothy K Grange
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Ruba Benini
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Abdulaziz S Alsaman
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Adel Mahmoud
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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Suleiman J, Hamwi N, El-Hattab AW. ATP13A2 novel mutations causing a rare form of juvenile-onset Parkinson disease. Brain Dev 2018; 40:824-826. [PMID: 29903538 DOI: 10.1016/j.braindev.2018.05.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/10/2018] [Accepted: 05/24/2018] [Indexed: 12/15/2022]
Abstract
Parkinson disease is a common neurodegenerative disease that typically starts around the age of 60 years; however, juvenile-onset disease can occur rarely. Although Parkinson disease is typically sporadic; in rare occasions, it can be caused by a single gene defect that is inherited in an autosomal dominant, autosomal recessive, or X-linked manner. Herein, we describe a 10-year-old child who had juvenile-onset parkinsonism with rigidity, bradykinesia, dystonia, gait disturbance, and cognitive impairment. Whole exome sequencing showed compound heterozygosity for two previously unreported novel mutations in ATP13A2 (PARK9): a paternally inherited c.1321A>T (p.I441F) and a maternally inherited c.3205G>A (p.A1069T). ATP13A2 mutations are rare cause of autosomal recessive juvenile-onset Parkinson disease. Family co-segregation study and the clinical phenotype support that p.I441F and p.A1069T are indeed disease-causing mutations.
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Affiliation(s)
- Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, and Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Nadia Hamwi
- Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Tawam Hospital, Al Ain, United Arab Emirates.
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Al Dhaibani MA, El-Hattab AW, Ismayl O, Suleiman J. B3GALNT2-Related Dystroglycanopathy: Expansion of the Phenotype with Novel Mutation Associated with Muscle-Eye-Brain Disease, Walker-Warburg Syndrome, Epileptic Encephalopathy-West Syndrome, and Sensorineural Hearing Loss. Neuropediatrics 2018; 49:289-295. [PMID: 29791932 DOI: 10.1055/s-0038-1651519] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mutations in B3GALNT2, encoding a glycosyltransferase enzyme involved in α-dystroglycan glycosylation, have been recently associated with dystroglycanopathy, a well-recognized subtype of congenital muscular dystrophy (CMD). Only a few cases have been reported with B3GALNT2-related dystroglycanopathy with variable severity ranging from mild CMD to severe muscle-eye-brain disease. Here, we describe a child with a novel homozygous nonsense mutation in B3GALNT2. The affected child has severe neurological disease since birth, including muscle disease manifested as hypotonia, muscle weakness, and wasting with elevated creatine kinase, eye disease including microphthalmia and blindness, brain disease with extensive brain malformations including massive hydrocephalus, diffuse cobblestone-lissencephaly, deformed craniocervical junction, and pontocerebellar hypoplasia. The clinical and radiologic findings are compatible with a diagnosis of severe muscle-eye-brain disease and more specifically Walker-Warburg syndrome. A more distinct aspect of the clinical phenotype in this child is the presence of refractory epilepsy in the form of epileptic spasms, epileptic encephalopathy, and West syndrome, as well as sensorineural hearing loss. These findings could expand the phenotype of B3GALNT2-related dystroglycanopathy. In this report, we also provide a detailed review of previously reported cases with B3GALNT2-related dystroglycanopathy and compare them to our reported child. In addition, we study the genotype-phenotype correlation in these cases.
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Affiliation(s)
- Muna A Al Dhaibani
- Pediatric Residency Program, Department of Pediatric, Tawam Hospital, Al Ain, United Arab Emirates
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Department of Pediatric, Tawam Hospital, Al Ain, United Arab Emirates
| | - Omar Ismayl
- Division of Neurology, Department of Pediatric, Sheikh Khalifa Medical City Hospital, Abu Dhabi, United Arab Emirates
| | - Jehan Suleiman
- Division of Neurology, Department of Pediatric, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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38
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Affiliation(s)
- Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Julia Wang
- Medical Scientist Training Program, Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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39
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Suleiman J, Al Hashem AM, Tabarki B, Al-Thihli K, Bi W, El-Hattab AW. PPP1R21 homozygous null variants associated with developmental delay, muscle weakness, distinctive facial features, and brain abnormalities. Clin Genet 2018; 94:351-355. [PMID: 29808498 DOI: 10.1111/cge.13387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 01/19/2023]
Abstract
We present 3 children with homozygous null variants in the PPP1R21 gene. A 3-year-old girl had profound developmental delay, hypotonia and weakness, poor feeding, recurrent chest infections and respiratory failure, rotatory nystagmus, absent reflexes, and a homozygous nonsense variant c.2089C>T (p.Arg697*). A 2-year-old boy had profound developmental delay, weakness and hypotonia, recurrent chest infections and respiratory distress, undescended testes, rotatory nystagmus, hyporeflexia, and a homozygous nonsense variant c.427C>T (p.Arg143*). An 11-year-old girl with profound developmental delay, weakness and hypotonia, stereotypic movements, growth failure, hyporeflexia, and a homozygous frameshift variant c.87_88delAG (p.Gly30Cysfs*4). In addition, these children shared common facial features (thick eyebrows, hypertelorism, broad nasal bridge, short nose with upturned nasal tip and broad low-hanging columella, thick lips, low-set ears, and coarse facies with excessive facial hair), and brain abnormalities (cerebellar vermis hypoplasia, ventricular dilatation, and reduced white matter volume). Although PPP1R21 has not yet been linked to human disease, the consistency in the phenotype of individuals from unrelated families, the nature of the variants which result in truncated proteins, and the expected vital role for PPP1R21 in cellular function, all support that PPP1R21 is a novel disease-associated gene responsible for the phenotype observed in these individuals.
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Affiliation(s)
- J Suleiman
- Division of Neurology, Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - A M Al Hashem
- Division of Genetics, Pediatrics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - B Tabarki
- Division of Neurology, Pediatrics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - K Al-Thihli
- Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Oman
| | - W Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics, Houston, Texas
| | - A W El-Hattab
- Division of Genetic and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates
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40
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Wang J, Kim E, Dai H, Stefans V, Vogel H, Al Jasmi F, Schrier Vergano SA, Castro D, Bernes S, Bhambhani V, Long C, El-Hattab AW, Wong LJ. Clinical and molecular spectrum of thymidine kinase 2-related mtDNA maintenance defect. Mol Genet Metab 2018; 124:124-130. [PMID: 29735374 DOI: 10.1016/j.ymgme.2018.04.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 11/29/2022]
Abstract
Mitochondrial DNA maintenance (mtDNA) defects have a wide range of causes, each with a set of phenotypes that overlap with many other neurological or muscular diseases. Clinicians face the challenge of narrowing down a long list of differential diagnosis when encountered with non-specific neuromuscular symptoms. Biallelic pathogenic variants in the Thymidine Kinase 2 (TK2) gene cause a myopathic form of mitochondrial DNA maintenance defect. Since the first description in 2001, there have been 71 patients reported with 42 unique pathogenic variants. Here we are reporting 11 new cases with 5 novel pathogenic variants. We describe and analyze a total of 82 cases with 47 unique TK2 pathogenic variants in effort to formulate a comprehensive molecular and clinical spectrum of TK2-related mtDNA maintenance disorders.
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Affiliation(s)
- Julia Wang
- Medical Scientist Training Program, Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States.
| | - Emily Kim
- Department of BioSciences, Rice University, 6100 Main Street, Houston, TX 77005, United States
| | - Honzheng Dai
- Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States
| | - Vikki Stefans
- UAMS College of Medicine, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72202, United States
| | - Hannes Vogel
- Pathology, Stanford University School of Medicine, R241 Edwards Building, 300 Pasteur Drive, Palo Alto, CA 94305, United States
| | - Fatma Al Jasmi
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Samantha A Schrier Vergano
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, 601 Children's Lane, Norfolk, VA 23507, United States
| | - Diana Castro
- Department of Pediatric, Neurology and Neurotherapeutics, Children's Health Dallas, University of Texas Southwestern, 2350 N Stemmons Freeway, Dallas, TX 75207, United States
| | - Saunder Bernes
- Department of Neurology, Phoenix Children's Hospital, Barrows Neurological Institute, 1919 East Thomas Road, Phoenix, AZ 85016, United States
| | - Vikas Bhambhani
- Genomics Medicine Program, Children's Hospital Minnesota, 2525 Chicago Ave S, Minneapolis, MN 55404, United States
| | - Catherine Long
- Genomics Medicine Program, Children's Hospital Minnesota, 2525 Chicago Ave S, Minneapolis, MN 55404, United States
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Lee-Jun Wong
- Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States.
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Abstract
Inborn errors of metabolism (IEM) are relatively uncommon causes for seizures in children; however, they should be considered in the differential diagnosis because several IEM are potentially treatable and seizures can be resolved if appropriate treatment is initiated. Clues from clinical presentation, physical examination, laboratory tests, and brain imaging can raise the possibility of IEM. Several IEM can present with seizures, either as the main presenting finding or as a part of a more complex phenotype. These include cofactor-related disorders, glycine and serine metabolism defects, and other disorders.
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Affiliation(s)
- Mohammed Almannai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Texas Children's Hospital, One Baylor Plaza, Houston, TX 77030, USA
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Tawam Roundabout, Al-Ain 15258, United Arab Emirates.
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Abstract
The phenotypic and genetic spectrum of ataxia with oculomotor apraxia (AOA) disorders is rapidly evolving and new technologies such as genetic mapping using whole exome sequencing reveal subtle distinctions among the various subtypes. We report a novel PNKP mutation in two siblings with progressive ataxia, abnormal saccades, sensorimotor neuropathy and dystonia consistent with the AOA type 4 phenotype. Laboratory evaluation revealed hypoalbuminemia, hypercholesterolemia with elevated LDL, elevated IgE levels and normal α fetoprotein levels. Eye movement examination demonstrated a marked saccade initiation defect with profound hypometric horizontal saccades. Vertical saccades were also affected but less so. Also present were conspicuous thrusting head movements when attempting to change gaze, but rather than an apraxia these were an adaptive strategy to take advantage of an intact vestibulo-ocular reflex to carry the eyes to a new target of interest. This is demonstrated in accompanying videos.
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Affiliation(s)
- Nicoline Schiess
- a Department of Neurology , Johns Hopkins Hospital , Baltimore , MD , USA
| | - David S Zee
- a Department of Neurology , Johns Hopkins Hospital , Baltimore , MD , USA
| | - Khurram A Siddiqui
- b Department of Neurology , Al Ain Hospital , Al Ain , United Arab Emirates
| | - Miklos Szolics
- c Department of Neurology , Tawam Hospital , Al Ain , United Arab Emirates
| | - Ayman W El-Hattab
- d Division of Clinical Genetics and Metabolic Disorders , Tawam Hospital , Al-Ain , United Arab Emirates
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43
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El-Hattab AW, Jahoor F. The utility of arginine-citrulline stable isotope tracer infusion technique in the assessment of nitric oxide production in MELAS syndrome. Int J Cardiol 2018; 254:282. [DOI: 10.1016/j.ijcard.2017.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 06/01/2017] [Indexed: 11/30/2022]
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44
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Glinton KE, Benke PJ, Lines MA, Geraghty MT, Chakraborty P, Al-Dirbashi OY, Jiang Y, Kennedy AD, Grotewiel MS, Sutton VR, Elsea SH, El-Hattab AW. Disturbed phospholipid metabolism in serine biosynthesis defects revealed by metabolomic profiling. Mol Genet Metab 2018; 123:309-316. [PMID: 29269105 DOI: 10.1016/j.ymgme.2017.12.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 01/28/2023]
Abstract
Serine biosynthesis defects are autosomal recessive metabolic disorders resulting from the deficiency of any of the three enzymes involved in de novo serine biosynthesis, specifically phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). In this study, we performed metabolomic profiling on 4 children with serine biosynthesis defects; 3 with PGDH deficiency and 1 with PSAT deficiency. The evaluations were performed at baseline and with serine and glycine supplementation. Metabolomic profiling performed at baseline showed low phospholipid species, including glycerophosphocholine, glycerophosphoethanolamine, and sphingomyelin. All children had low serine and glycine as expected. Low glycerophosphocholine compounds were found in 4 children, low glycerophosphoethanolamine compounds in 3 children, and low sphingomyelin species in 2 children. Metabolic profiling with serine and glycine supplementation showed normalization of most of the low phospholipid compounds in the 4 children. Phospholipids are the major component of plasma and intracellular membranes, and phosphatidylcholine is the most abundant phospholipid of all mammalian cell types and subcellular organelles. Phosphatidylcholine is of particular importance for the nervous system, where it is essential for neuronal differentiation. The observed low phosphatidylcholine species in children with serine biosynthesis defects that improved after serine supplementation, supports the role of serine as a significant precursor for phosphatidylcholine. The vital role that phosphatidylcholine has during neuronal differentiation and the pronounced neurological manifestations in serine biosynthesis defects suggest that phosphatidylcholine deficiency occurring secondary to serine deficiency may have a significant contribution to the development of the neurological manifestations in individuals with serine biosynthesis defects.
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Affiliation(s)
- Kevin E Glinton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Paul J Benke
- Joe DiMaggio Children's Hospital and Florida Atlantic School of Medicine, Hollywood, FL, USA
| | - Matthew A Lines
- Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | | | | | - Osama Y Al-Dirbashi
- Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; College of Medicine and Health Sciences, United Arab Emirate University, Al-Ain, United Arab Emirates
| | - Yi Jiang
- Baylor Genetics, Houston, TX, USA
| | | | - Michael S Grotewiel
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Baylor Genetics, Houston, TX, USA
| | - Ayman W El-Hattab
- Division of Clinical Genetic and Metabolic Disorders, Tawam Hospital, Al-Ain, United Arab Emirates.
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El-Hattab AW, Wang J, Dai H, Almannai M, Staufner C, Alfadhel M, Gambello MJ, Prasun P, Raza S, Lyons HJ, Afqi M, Saleh MAM, Faqeih EA, Alzaidan HI, Alshenqiti A, Flore LA, Hertecant J, Sacharow S, Barbouth DS, Murayama K, Shah AA, Lin HC, Wong LJC. MPV17-related mitochondrial DNA maintenance defect: New cases and review of clinical, biochemical, and molecular aspects. Hum Mutat 2018; 39:461-470. [PMID: 29282788 DOI: 10.1002/humu.23387] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/04/2017] [Accepted: 12/15/2017] [Indexed: 02/02/2023]
Abstract
Mitochondrial DNA (mtDNA) maintenance defects are a group of diseases caused by deficiency of proteins involved in mtDNA synthesis, mitochondrial nucleotide supply, or mitochondrial dynamics. One of the mtDNA maintenance proteins is MPV17, which is a mitochondrial inner membrane protein involved in importing deoxynucleotides into the mitochondria. In 2006, pathogenic variants in MPV17 were first reported to cause infantile-onset hepatocerebral mtDNA depletion syndrome and Navajo neurohepatopathy. To date, 75 individuals with MPV17-related mtDNA maintenance defect have been reported with 39 different MPV17 pathogenic variants. In this report, we present an additional 25 affected individuals with nine novel MPV17 pathogenic variants. We summarize the clinical features of all 100 affected individuals and review the total 48 MPV17 pathogenic variants. The vast majority of affected individuals presented with an early-onset encephalohepatopathic disease characterized by hepatic and neurological manifestations, failure to thrive, lactic acidemia, and mtDNA depletion detected mainly in liver tissue. Rarely, MPV17 deficiency can cause a late-onset neuromyopathic disease characterized by myopathy and peripheral neuropathy with no or minimal liver involvement. Approximately half of the MPV17 pathogenic variants are missense. A genotype with biallelic missense variants, in particular homozygous p.R50Q, p.P98L, and p.R41Q, can carry a relatively better prognosis.
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Affiliation(s)
- Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatric Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Julia Wang
- Medical Scientist Training Program and Program in Developmental Biology, Baylor College of Medicine, Houston, Texas
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Mohammed Almannai
- Section of Medical Genetics, King Fahad Medical City, Children's Specialist Hospital, Riyadh, Saudi Arabia
| | - Christian Staufner
- Division of Neuropediatrics and Metabolic Medicine, Department of General Pediatrics, University Hospital Heidelberg, Heidelberg, Germany
| | - Majid Alfadhel
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Michael J Gambello
- Division of Medical Genetics, Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - Pankaj Prasun
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Saleem Raza
- Department of Pediatrics, St John Hospital and Medical Center and Wayne State University School of Medicine, Detroit, Michigan
| | - Hernando J Lyons
- Department of Pediatrics, St John Hospital and Medical Center and Wayne State University School of Medicine, Detroit, Michigan
| | - Manal Afqi
- Section of Medical Genetics, King Fahad Medical City, Children's Specialist Hospital, Riyadh, Saudi Arabia
| | - Mohammed A M Saleh
- Section of Medical Genetics, King Fahad Medical City, Children's Specialist Hospital, Riyadh, Saudi Arabia
| | - Eissa A Faqeih
- Section of Medical Genetics, King Fahad Medical City, Children's Specialist Hospital, Riyadh, Saudi Arabia
| | - Hamad I Alzaidan
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abduljabbar Alshenqiti
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Leigh Anne Flore
- Division of Genetic, Genomic, and Metabolic Disorders, Children's Hospital of Michigan and Wayne State University, Detroit, Michigan
| | - Jozef Hertecant
- Division of Clinical Genetics and Metabolic Disorders, Pediatric Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Stephanie Sacharow
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Deborah S Barbouth
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miller School of Medicine, Miami, Florida
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, Chiba, Japan
| | - Amit A Shah
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Henry C Lin
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
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46
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Al Mutairi F, Alfadhel M, Nashabat M, El-Hattab AW, Ben-Omran T, Hertecant J, Eyaid W, Ali R, Alasmari A, Kara M, Al-Twaijri W, Filimban R, Alshenqiti A, Al-Owain M, Faqeih E, Alkuraya FS. Phenotypic and Molecular Spectrum of Aicardi-Goutières Syndrome: A Study of 24 Patients. Pediatr Neurol 2018; 78:35-40. [PMID: 29239743 DOI: 10.1016/j.pediatrneurol.2017.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/24/2017] [Accepted: 09/02/2017] [Indexed: 01/24/2023]
Abstract
BACKGROUND Aicardi-Goutières syndrome is a rare genetic neurological disorder with variable clinical manifestations. Molecular detection of specific mutations is required to confirm the diagnosis. The aim of this study was to review the clinical and molecular diagnostic findings in 24 individuals with Aicardi-Goutières syndrome who presented during childhood in an Arab population. MATERIALS AND METHODS We reviewed the records of 24 patients from six tertiary hospitals in different Arab countries. All included patients had a molecular diagnosis of Aicardi-Goutières syndrome. RESULTS Six individuals with Aicardi-Goutières syndrome (25%) had a neonatal presentation, whereas the remaining patients presented during the first year of life. Patients presented with developmental delay (24 cases, 100%); spasticity (24 cases, 100%); speech delay (23 cases, 95.8%); profound intellectual disability (21 cases, 87.5%); truncal hypotonia (21 cases, 87.5%); seizures (eighteen cases, 75%); and epileptic encephalopathy (15 cases, 62.5%). Neuroimaging showed white matter abnormalities (22 cases, 91.7%), cerebral atrophy (75%), and small, multifocal calcifications in the lentiform nuclei and deep cerebral white matter (54.2%). Homozygous mutations were identified in RNASEH2B (54.2%), RNASEH2A (20.8%), RNASEH2C (8.3%), SAMHD1 (8.3%), TREX1 (4.2%), and heterozygous mutations in IFIH1 (4.2%), with c.356A>G (p.Asp119Gly) in RNASEH2B being the most frequent mutation. Three novel mutations c.987delT and c.625 + 1G>A in SAMHD1 gene and c.961G>T in the IFIHI1 gene were identified. CONCLUSIONS This is the largest molecularly confirmed Aicardi-Goutières syndrome cohort from Arabia. By presenting these clinical and molecular findings, we hope to raise awareness of Aicardi-Goutières syndrome and to demonstrate the importance of specialist referral and molecular diagnosis.
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Affiliation(s)
- Fuad Al Mutairi
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia.
| | - Majid Alfadhel
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Marwan Nashabat
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Tawam Hospital, Al Ain, United Arab Emirates
| | - Tawfeg Ben-Omran
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Qatar
| | - Jozef Hertecant
- Division of Clinical Genetics and Metabolic Disorders, Tawam Hospital, Al Ain, United Arab Emirates
| | - Wafaa Eyaid
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Rehab Ali
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Qatar
| | - Ali Alasmari
- Medical Genetics Section, King Fahad Medical City, Children's Hospital, Riyadh, Saudi Arabia
| | - Majdi Kara
- Department of Pediatrics, University of Tripoli, Tripoli, Libya
| | - Waleed Al-Twaijri
- King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, Division of Neurology, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Rana Filimban
- Medical Genetics Section, King Fahad Medical City, Children's Hospital, Riyadh, Saudi Arabia
| | - Abduljabbar Alshenqiti
- Department of Medical Genetics, King Faisal Specialist Hospital, and Research Center, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital, and Research Center, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Medical Genetics Section, King Fahad Medical City, Children's Hospital, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Medical Genetics, King Faisal Specialist Hospital, and Research Center, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Anazi S, Maddirevula S, Salpietro V, Asi YT, Alsahli S, Alhashem A, Shamseldin HE, AlZahrani F, Patel N, Ibrahim N, Abdulwahab FM, Hashem M, Alhashmi N, Al Murshedi F, Al Kindy A, Alshaer A, Rumayyan A, Al Tala S, Kurdi W, Alsaman A, Alasmari A, Banu S, Sultan T, Saleh MM, Alkuraya H, Salih MA, Aldhalaan H, Ben-Omran T, Al Musafri F, Ali R, Suleiman J, Tabarki B, El-Hattab AW, Bupp C, Alfadhel M, Al Tassan N, Monies D, Arold ST, Abouelhoda M, Lashley T, Houlden H, Faqeih E, Alkuraya FS. Correction to: Expanding the genetic heterogeneity of intellectual disability. Hum Genet 2017; 137:105-109. [PMID: 29288388 DOI: 10.1007/s00439-017-1859-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Variant nomenclature discrepancy was identified in the article.
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Affiliation(s)
- Shams Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Vincenzo Salpietro
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Yasmine T Asi
- Queen Square Brain Bank for Neurological Disorders, Department of Molecular Neuroscience, UCL Institute of Neurology, University College London, London, UK
| | - Saud Alsahli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema AlZahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous M Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nadia Alhashmi
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Fathiya Al Murshedi
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Adila Al Kindy
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Ahmad Alshaer
- Pediatric Neurology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ahmed Rumayyan
- King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Neurology Division, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Saeed Al Tala
- Department of Pediatrics and Genetic Unit, Armed Forces Hospital Khamis Mushayt, Riyadh, Saudi Arabia
| | - Wesam Kurdi
- Department of Obstetrics and Gynecology, King Faisal Specialist Hospital, Riyadh, Saudi Arabia
| | - Abdulaziz Alsaman
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Alasmari
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Selina Banu
- Department of Pediatric Neurology, ICH and SSF Hospital Mirpur, Dhaka, 1216, Bangladesh
| | - Tipu Sultan
- Department of Pediatric Neurology, Institute of Child Health and The Children's Hospital Lahore, 381-D/2, Lahore, Pakistan
| | - Mohammed M Saleh
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Hisham Alkuraya
- Department of Ophthalmology, Specialized Medical Center Hospital, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Hesham Aldhalaan
- Pediatric Neurology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tawfeg Ben-Omran
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Fatima Al Musafri
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Rehab Ali
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
| | - Brahim Tabarki
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Department of Pediatrics, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Caleb Bupp
- Spectrum Health Genetics, Grand Rapids, MI, USA
| | - Majid Alfadhel
- Genetics Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Nada Al Tassan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Stefan T Arold
- Division of Biological and Environmental Sciences and Engineering (BESE), Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Disorders, Department of Molecular Neuroscience, UCL Institute of Neurology, University College London, London, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia. .,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia. .,Spectrum Health Genetics, Grand Rapids, MI, USA. .,Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
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48
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Al Dhaibani MA, El-Hattab AW, Holroyd KB, Orthmann-Murphy J, Larson VA, Siddiqui KA, Szolics M, Schiess N. Novel mutation in the KCNJ10 gene in three siblings with seizures, ataxia and no electrolyte abnormalities. J Neurogenet 2017; 32:1-5. [PMID: 29191078 DOI: 10.1080/01677063.2017.1404057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report a consanguineous family with three affected siblings with novel mutation in the KCNJ10 gene. All three presented with central nervous system symptoms in the form of infantile focal seizures, ataxia, slurred speech with early developmental delay and intellectual disability in two siblings. None had any associated electrolyte abnormalities and no symptomatic hearing deficits were observed.
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Affiliation(s)
- Muna A Al Dhaibani
- a Department of Pediatrics , Tawam Hospital , Al Ain , United Arab Emirates
| | - Ayman W El-Hattab
- b Division of Clinical Genetics and Metabolic Disorders Pediatrics Department , Tawam Hospital , Al Ain , United Arab Emirates
| | | | | | - Valerie A Larson
- d Johns Hopkins Hospital and Health System , Baltimore , MD , USA
| | | | - Miklos Szolics
- f Department of Neurology , Al Tawam Hospital , Al Ain , United Arab Emirates
| | - Nicoline Schiess
- g Department of Neurology , Johns Hopkins University , Baltimore , MD , USA
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49
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Sadikovic B, Wang J, El-Hattab AW, Landsverk M, Douglas G, Brundage EK, Craigen WJ, Schmitt ES, Wong LJC. Correction: Sequence Homology at the Breakpoint and Clinical Phenotype of Mitochondrial DNA Deletion Syndromes. PLoS One 2017; 12:e0188610. [PMID: 29155871 PMCID: PMC5695760 DOI: 10.1371/journal.pone.0188610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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50
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El-Hattab AW, Zarante AM, Almannai M, Scaglia F. Therapies for mitochondrial diseases and current clinical trials. Mol Genet Metab 2017; 122:1-9. [PMID: 28943110 PMCID: PMC5773113 DOI: 10.1016/j.ymgme.2017.09.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 01/10/2023]
Abstract
Mitochondrial diseases are a clinically and genetically heterogeneous group of disorders that result from dysfunction of the mitochondrial oxidative phosphorylation due to molecular defects in genes encoding mitochondrial proteins. Despite the advances in molecular and biochemical methodologies leading to better understanding of the etiology and mechanism of these diseases, there are still no satisfactory therapies available for mitochondrial disorders. Treatment for mitochondrial diseases remains largely symptomatic and does not significantly alter the course of the disease. Based on limited number of clinical trials, several agents aiming at enhancing mitochondrial function or treating the consequences of mitochondrial dysfunction have been used. Several agents are currently being evaluated for mitochondrial diseases. Therapeutic strategies for mitochondrial diseases include the use of agents enhancing electron transfer chain function (coenzyme Q10, idebenone, riboflavin, dichloroacetate, and thiamine), agents acting as energy buffer (creatine), antioxidants (vitamin C, vitamin E, lipoic acid, cysteine donors, and EPI-743), amino acids restoring nitric oxide production (arginine and citrulline), cardiolipin protector (elamipretide), agents enhancing mitochondrial biogenesis (bezafibrate, epicatechin, and RTA 408), nucleotide bypass therapy, liver transplantation, and gene therapy. Although, there is a lack of curative therapies for mitochondrial disorders at the current time, the increased number of clinical research evaluating agents that target different aspects of mitochondrial dysfunction is promising and is expected to generate more therapeutic options for these diseases in the future.
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Affiliation(s)
- Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | | | - Mohammed Almannai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA.
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