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The Power of Clinical Diagnosis for Deciphering Complex Genetic Mechanisms in Rare Diseases. Genes (Basel) 2023; 14:genes14010196. [PMID: 36672937 PMCID: PMC9858967 DOI: 10.3390/genes14010196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Complex genetic disease mechanisms, such as structural or non-coding variants, currently pose a substantial difficulty in frontline diagnostic tests. They thus may account for most unsolved rare disease patients regardless of the clinical phenotype. However, the clinical diagnosis can narrow the genetic focus to just a couple of genes for patients with well-established syndromes defined by prominent physical and/or unique biochemical phenotypes, allowing deeper analyses to consider complex genetic origin. Then, clinical-diagnosis-driven genome sequencing strategies may expedite the development of testing and analytical methods to account for complex disease mechanisms as well as to advance functional assays for the confirmation of complex variants, clinical management, and the development of new therapies.
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The Value of a Comprehensive Genomic Evaluation in Prenatal Diagnosis of Genetic Diseases: A Retrospective Study. Genes (Basel) 2022; 13:genes13122365. [PMID: 36553632 PMCID: PMC9778469 DOI: 10.3390/genes13122365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Currently, there are still many challenges in prenatal diagnosis, such as limited or uncertain fetal phenotyping, variant interpretation, and rapid turnaround times. The aim of this study was to illustrate the value of a comprehensive genomic evaluation in prenatal diagnosis. We retrospectively reviewed 20 fetuses with clinically significant copy number variants (CNVs) detected by chromosomal microarray analysis (CMA) and no further exome sequencing testing in our tertiary center between 2019 and 2020. The residual DNA from the prenatal cases was used for the parallel implementation of CNV sequencing (CNV-seq) and trio-based clinical exome sequencing (trio-CES). CMA revealed 26 clinically significant CNVs (18 deletions and eight duplications) in 20 fetuses, in which five fetuses had two or more CNVs. There were eight fetuses with pathogenic CNVs (e.g., del 1p36), nine fetuses with likely pathogenic CNVs (e.g., dup 22q11.21), and three fetuses with variants of unknown significance (VOUS, e.g., dup 1q21.1q21.2). Trio-CES identified four fetuses with likely pathogenic mutations (SNV/InDels). Of note, a fetus was detected with a maternally inherited hemizygous variant in the SLX4 gene due to a 16p13.3 deletion on the paternal chromosome. The sizes of CNVs detected by CNV-seq were slightly larger than that of the SNP array, and four cases with mosaic CNVs were all identified by CNV-seq. In conclusion, microdeletion/duplication syndromes and monogenic disorders may co-exist in a subject, and CNV deletion may contribute to uncovering additional recessive disease alleles. The application of a comprehensive genomic evaluation (CNVs and SNV/InDels) has great value in the prenatal diagnosis arena. CNV-seq based on NGS technology is a reliable and a cost-effective technique for identifying CNVs.
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ElSheikh RH, Aravindhan A, Boysen S, Veerapandiyan A. Infantile-Onset Complex Hereditary Spastic Paraplegia Due to a Novel Mutation in SPAST Gene. Pediatr Neurol 2022; 134:71. [PMID: 35841713 DOI: 10.1016/j.pediatrneurol.2022.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/22/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Reem H ElSheikh
- Division of Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, Arkansas
| | - Akilandeswari Aravindhan
- Division of Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, Arkansas
| | - Sebastian Boysen
- Division of Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, Arkansas
| | - Aravindhan Veerapandiyan
- Division of Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, Arkansas.
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Maroilley T, Wright NAM, Diao C, MacLaren L, Pfeffer G, Sarna JR, Billie Au PY, Tarailo-Graovac M. Case Report: Biallelic Loss of Function ATM due to Pathogenic Synonymous and Novel Deep Intronic Variant c.1803-270T > G Identified by Genome Sequencing in a Child With Ataxia–Telangiectasia. Front Genet 2022; 13:815210. [PMID: 35145552 PMCID: PMC8822238 DOI: 10.3389/fgene.2022.815210] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 11/26/2022] Open
Abstract
Ataxia–telangiectasia (AT) is a complex neurodegenerative disease with an increased risk for bone marrow failure and malignancy. AT is caused by biallelic loss of function variants in ATM, which encodes a phosphatidylinositol 3-kinase that responds to DNA damage. Herein, we report a child with progressive ataxia, chorea, and genome instability, highly suggestive of AT. The clinical ataxia gene panel identified a maternal heterozygous synonymous variant (NM_000051.3: c.2250G > A), previously described to result in exon 14 skipping. Subsequently, trio genome sequencing led to the identification of a novel deep intronic variant [NG_009830.1(NM_000051.3): c.1803-270T > G] inherited from the father. Transcript analyses revealed that c.1803-270T > G results in aberrant inclusion of 56 base pairs of intron 11. In silico tests predicted a premature stop codon as a consequence, suggesting non-functional ATM; and DNA repair analyses confirmed functional loss of ATM. Our findings highlight the power of genome sequencing, considering deep intronic variants in undiagnosed rare disease patients.
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Affiliation(s)
- Tatiana Maroilley
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Nicola A. M. Wright
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Section of Pediatric Hematology-Immunology, Department of Pediatrics, Alberta Children’s Hospital, University of Calgary, Calgary, AB, Canada
| | - Catherine Diao
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Linda MacLaren
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Gerald Pfeffer
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Justyna R. Sarna
- Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Ping Yee Billie Au
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- *Correspondence: Ping Yee Billie Au, ; Maja Tarailo-Graovac,
| | - Maja Tarailo-Graovac
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- *Correspondence: Ping Yee Billie Au, ; Maja Tarailo-Graovac,
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May HJ, Fasheun JA, Bain JM, Baugh EH, Bier LE, Revah-Politi A, Roye DP, Goldstein DB, Carmel JB. Genetic testing in individuals with cerebral palsy. Dev Med Child Neurol 2021; 63:1448-1455. [PMID: 34114234 PMCID: PMC9277698 DOI: 10.1111/dmcn.14948] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/30/2021] [Indexed: 12/28/2022]
Abstract
AIM To determine which patients with cerebral palsy (CP) should undergo genetic testing, we compared the rate of likely causative genetic variants from whole-exome sequencing in individuals with and without environmental risk factors. METHOD Patients were part of a convenience and physician-referred cohort recruited from a single medical center, and research whole-exome sequencing was completed. Participants were evaluated for the following risk factors: extreme preterm birth, brain bleed or stroke, birth asphyxia, brain malformations, and intrauterine infection. RESULTS A total of 151 unrelated individuals with CP (81 females, 70 males; mean age 25y 7mo [SD 17y 5mo], range 3wks-72y) participated. Causative genetic variants were identified in 14 participants (9.3%). There was no significant difference in diagnostic rate between individuals with risk factors (10 out of 123; 8.1%) and those without (4 out of 28; 14.3%) (Fisher's exact p=0.3). INTERPRETATION While the rate of genetic diagnoses among individuals without risk factors was higher than those with risk factors, the difference was not statistically significant at this sample size. The identification of genetic diagnoses in over 8% of cases with risk factors suggests that these might confer susceptibility to environmental factors, and that further research should include individuals with risk factors. What this paper adds There is no significant difference in diagnostic rate between individuals with and without risk factors. Genetic variants may confer susceptibility to environmental risk factors. Six causative variants were identified in genes not previously associated with cerebral palsy. Global developmental delay/intellectual disability is positively associated with a genetic etiology. Extreme preterm birth, stroke/brain hemorrhage, and older age are negatively associated with a genetic etiology.
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Affiliation(s)
- Halie J. May
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY
| | - Jennifer A. Fasheun
- Weinberg Family Cerebral Palsy Center, Department of Orthopedics, Columbia University Irving Medical Center, New York, NY
| | - Jennifer M. Bain
- Department of Neurology, Columbia University Irving Medical Center, New York, NY
| | - Evan H. Baugh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY
| | - Louise E. Bier
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY
| | - Anya Revah-Politi
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY
| | - David P. Roye
- Weinberg Family Cerebral Palsy Center, Department of Orthopedics, Columbia University Irving Medical Center, New York, NY
| | - David B. Goldstein
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY
| | - Jason B. Carmel
- Weinberg Family Cerebral Palsy Center, Department of Orthopedics, Columbia University Irving Medical Center, New York, NY,Department of Neurology, Columbia University Irving Medical Center, New York, NY
| | - NYP/CUIMC Genomics Team
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY,Weinberg Family Cerebral Palsy Center, Department of Orthopedics, Columbia University Irving Medical Center, New York, NY,Department of Neurology, Columbia University Irving Medical Center, New York, NY,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY,Division of Clinical Genetics, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY
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Abstract
Autism is a common and complex neurologic disorder whose scientific underpinnings have begun to be established in the past decade. The essence of this breakthrough has been a focus on families, where genetic analyses are strongest, versus large-scale, case-control studies. Autism genetics has progressed in parallel with technology, from analyses of copy number variation to whole-exome sequencing (WES) and whole-genome sequencing (WGS). Gene mutations causing complete loss of function account for perhaps one-third of cases, largely detected through WES. This limitation has increased interest in understanding the regulatory variants of genes that contribute in more subtle ways to the disorder. Strategies combining biochemical analysis of gene regulation, WGS analysis of the noncoding genome, and machine learning have begun to succeed. The emerging picture is that careful control of the amounts of transcription, mRNA, and proteins made by key brain genes-stoichiometry-plays a critical role in defining the clinical features of autism.
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Affiliation(s)
- Robert B Darnell
- Laboratory of Molecular Neuro-Oncology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA;
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Angelini C, Goizet C, Said SA, Camu W, Depienne C, Heron B, Kol B, Guillaud-Bataille M, Pennamen P, Rooryck C, Scherer-Gagou C, Tissier L, Stevanin G, Leguern E, Banneau G. Evidence of mosaicism in SPAST variant carriers in four French families. Eur J Hum Genet 2021; 29:1158-1163. [PMID: 33958741 PMCID: PMC8298572 DOI: 10.1038/s41431-021-00847-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 02/14/2021] [Accepted: 02/24/2021] [Indexed: 11/08/2022] Open
Abstract
Hereditary spastic paraplegias (HSP) are heterogeneous disorders, with more than 70 causative genes. Variants in SPAST are the most frequent genetic etiology and are responsible for spastic paraplegia type 4 (SPG4). Age at onset can vary, even between patients from the same family, and incomplete penetrance is described. Somatic mosaicism is extremely rare with only three patients reported in the literature. We report here SPAST mosaic variants in four unrelated patients. We confirm that mosaicism in SPAST is a very rare event with only four identified cases on more than 300 patients with a SPAST variant previously described by our clinical diagnostic laboratory.
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Affiliation(s)
- Chloé Angelini
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, Bordeaux, France
- Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France
| | - Cyril Goizet
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, Bordeaux, France
- Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France
- INSERM U1211, laboratoire MRGM, Univ. Bordeaux, Bordeaux, France
| | - Samia Ait Said
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
| | - William Camu
- Centre de référence SLA, explorations neurologiques, CHU et Univ Montpellier, Montpellier, France
| | - Christel Depienne
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
- Sorbonne université, Institut du Cerveau, INSERM U 1127, Paris, France
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Bénédicte Heron
- Service de Neurologie Pédiatrique, Hôpital Armand Trousseau-La Roche Guyon, GHUEP, APHP, Paris, France
| | - Bophara Kol
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
| | | | - Perrine Pennamen
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, Bordeaux, France
- INSERM U1211, laboratoire MRGM, Univ. Bordeaux, Bordeaux, France
| | - Caroline Rooryck
- Service de Génétique Médicale, CHU Bordeaux, Bordeaux, Bordeaux, France
- INSERM U1211, laboratoire MRGM, Univ. Bordeaux, Bordeaux, France
| | - Clarisse Scherer-Gagou
- Centre National de Référence pour les Maladies Neurogénétiques de l'Adulte, Département de Neurologie, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Laurène Tissier
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
| | - Giovanni Stevanin
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
- Sorbonne université, Institut du Cerveau, INSERM U 1127, Paris, France
- Equipe de neurogénétique, Ecole Pratique des Hautes Etudes (EPHE), PSL Research University, Paris, France
| | - Eric Leguern
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France.
- Sorbonne université, Institut du Cerveau, INSERM U 1127, Paris, France.
| | - Guillaume Banneau
- Sorbonne Université, AP-HP, GH Pitié-Salpêtrière, Département de génétique, Paris, France
- Département de Génétique Médicale, Institut Fédératif de Biologie, Hôpital Purpan, Toulouse, France
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Baldwin I, Shafer RL, Hossain WA, Gunewardena S, Veatch OJ, Mosconi MW, Butler MG. Genomic, Clinical, and Behavioral Characterization of 15q11.2 BP1-BP2 Deletion (Burnside-Butler) Syndrome in Five Families. Int J Mol Sci 2021; 22:1660. [PMID: 33562221 PMCID: PMC7914695 DOI: 10.3390/ijms22041660] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/02/2021] [Indexed: 01/07/2023] Open
Abstract
The 15q11.2 BP1-BP2 deletion (Burnside-Butler) syndrome is emerging as the most common cytogenetic finding in patients with neurodevelopmental or autism spectrum disorders (ASD) presenting for microarray genetic testing. Clinical findings in Burnside-Butler syndrome include developmental and motor delays, congenital abnormalities, learning and behavioral problems, and abnormal brain findings. To better define symptom presentation, we performed comprehensive cognitive and behavioral testing, collected medical and family histories, and conducted clinical genetic evaluations. The 15q11.2 BP1-BP2 region includes the TUBGCP5, CYFIP1, NIPA1, and NIPA2 genes. To determine if additional genomic variation outside of the 15q11.2 region influences expression of symptoms in Burnside-Butler syndrome, whole-exome sequencing was performed on the parents and affected children for the first time in five families with at least one parent and child with the 15q1l.2 BP1-BP2 deletion. In total, there were 453 genes with possibly damaging variants identified across all of the affected children. Of these, 99 genes had exclusively de novo variants and 107 had variants inherited exclusively from the parent without the deletion. There were three genes (APBB1, GOLGA2, and MEOX1) with de novo variants that encode proteins evidenced to interact with CYFIP1. In addition, one other gene of interest (FAT3) had variants inherited from the parent without the deletion and encoded a protein interacting with CYFIP1. The affected individuals commonly displayed a neurodevelopmental phenotype including ASD, speech delay, abnormal reflexes, and coordination issues along with craniofacial findings and orthopedic-related connective tissue problems. Of the 453 genes with variants, 35 were associated with ASD. On average, each affected child had variants in 6 distinct ASD-associated genes (x¯ = 6.33, sd = 3.01). In addition, 32 genes with variants were included on clinical testing panels from Clinical Laboratory Improvement Amendments (CLIA) approved and accredited commercial laboratories reflecting other observed phenotypes. Notably, the dataset analyzed in this study was small and reported results will require validation in larger samples as well as functional follow-up. Regardless, we anticipate that results from our study will inform future research into the genetic factors influencing diverse symptoms in patients with Burnside-Butler syndrome, an emerging disorder with a neurodevelopmental behavioral phenotype.
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Affiliation(s)
- Isaac Baldwin
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA; (I.B.); (W.A.H.); (O.J.V.)
- Department of Pediatrics, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA
| | - Robin L. Shafer
- Schiefelbusch Institute for Life Span Studies and Kansas Center for Autism Research and Training, University of Kansas, Lawrence, KS 66045, USA; (R.L.S.); (M.W.M.)
| | - Waheeda A. Hossain
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA; (I.B.); (W.A.H.); (O.J.V.)
- Department of Pediatrics, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA
| | - Sumedha Gunewardena
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Olivia J. Veatch
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA; (I.B.); (W.A.H.); (O.J.V.)
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Matthew W. Mosconi
- Schiefelbusch Institute for Life Span Studies and Kansas Center for Autism Research and Training, University of Kansas, Lawrence, KS 66045, USA; (R.L.S.); (M.W.M.)
- Clinical Child Psychology Program, University of Kansas, Lawrence, KS 66045, USA
| | - Merlin G. Butler
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA; (I.B.); (W.A.H.); (O.J.V.)
- Department of Pediatrics, University of Kansas Medical Center, 3901 Rainbow Blvd. MS 4015, Kansas City, KS 66160, USA
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Zhang H, Yue F, Zhang X, He J, Jiang Y, Liu R, Yu Y. Prenatal detection of distal 1q21.1q21.2 microduplication with abnormal ultrasound findings: Two cases report and literature review. Medicine (Baltimore) 2021; 100:e24227. [PMID: 33429818 PMCID: PMC7793324 DOI: 10.1097/md.0000000000024227] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 12/17/2020] [Indexed: 01/05/2023] Open
Abstract
RATIONALE 1q21.1 duplication is an uncommon chromosomal submicroscopic imbalance which is associated with growth/mental retardation, dysmorphic features, autism, multiple congenital and neuropsychiatric disorders. PATIENT CONCERNS Two pregnant women underwent amniocentesis for cytogenetic analysis and chromosomal microarray analysis (CMA) following abnormal ultrasound findings. Case 1 presented short nasal bone and case 2 showed absent nasal bone, ventricular septal defect and umbilical cord circling in ultrasonic examination. DIAGNOSES G-banding analysis showed that the two fetuses presented normal karyotypic results while CMA detected 1.796 Mb (case 1) and 1.242 Mb (case 2) microduplications in the region of 1q21.1q21.2 separately. Furthermore, the CMA also revealed a 1.2 Mb microdeletion of 8p23.3 in case 1. INTERVENTIONS The couple in case 1 chose to terminate the pregnancy, while the couple in case 2 continued the pregnancy and finally delivered a male infant who presented low nasal bridge and ventricular septal defect. OUTCOMES The 1q21.1q21.2 duplications in our report were located in the distal 1q21.1 region, overlapping with 1q21.1 duplication syndrome. Case 2 was the first reported live birth with 1q21.1 duplication according to prenatal CMA detection in China. LESSONS The genotype-phenotype of 1q21.1 duplication is complicated due to the phenotypic diversity, incomplete penetrance, and lack of obvious characteristics. So it is difficult to predict the postnatal development and health conditions clinically. Hence, long term follow up is necessary for newborn infants with 1q21.1 duplication, irrespective of whether the duplication is de novo or inherited.
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Affiliation(s)
- Hongguo Zhang
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Fagui Yue
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Xinyue Zhang
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Jing He
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Yuting Jiang
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Ruizhi Liu
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
| | - Yang Yu
- Center for Reproductive Medicine, Center for Prenatal Diagnosis, First Hospital
- Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China
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Maroilley T, Tarailo-Graovac M. Uncovering Missing Heritability in Rare Diseases. Genes (Basel) 2019; 10:E275. [PMID: 30987386 PMCID: PMC6523881 DOI: 10.3390/genes10040275] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022] Open
Abstract
The problem of 'missing heritability' affects both common and rare diseases hindering: discovery, diagnosis, and patient care. The 'missing heritability' concept has been mainly associated with common and complex diseases where promising modern technological advances, like genome-wide association studies (GWAS), were unable to uncover the complete genetic mechanism of the disease/trait. Although rare diseases (RDs) have low prevalence individually, collectively they are common. Furthermore, multi-level genetic and phenotypic complexity when combined with the individual rarity of these conditions poses an important challenge in the quest to identify causative genetic changes in RD patients. In recent years, high throughput sequencing has accelerated discovery and diagnosis in RDs. However, despite the several-fold increase (from ~10% using traditional to ~40% using genome-wide genetic testing) in finding genetic causes of these diseases in RD patients, as is the case in common diseases-the majority of RDs are also facing the 'missing heritability' problem. This review outlines the key role of high throughput sequencing in uncovering genetics behind RDs, with a particular focus on genome sequencing. We review current advances and challenges of sequencing technologies, bioinformatics approaches, and resources.
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Affiliation(s)
- Tatiana Maroilley
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Maja Tarailo-Graovac
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
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Boutry M, Morais S, Stevanin G. Update on the Genetics of Spastic Paraplegias. Curr Neurol Neurosci Rep 2019; 19:18. [DOI: 10.1007/s11910-019-0930-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Matthews AM, Blydt-Hansen I, Al-Jabri B, Andersen J, Tarailo-Graovac M, Price M, Selby K, Demos M, Connolly M, Drögemoller B, Shyr C, Mwenifumbo J, Elliott AM, Lee J, Ghani A, Stöckler S, Salvarinova R, Vallance H, Sinclair G, Ross CJ, Wasserman WW, McKinnon ML, Horvath GA, Goez H, van Karnebeek CD. Atypical cerebral palsy: genomics analysis enables precision medicine. Genet Med 2018; 21:1621-1628. [DOI: 10.1038/s41436-018-0376-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 11/08/2018] [Indexed: 11/09/2022] Open
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