1
|
Thompson MD. Innovations in Phenotyping and Diagnostics Create Opportunities for Improved Treatment and Genetic Counseling for Rare Diseases. Genes (Basel) 2024; 15:715. [PMID: 38927651 PMCID: PMC11203049 DOI: 10.3390/genes15060715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
Genetic counseling and treatment options for rare developmental disabilities (DDs) have been revolutionized by the opportunities made possible by using massively parallel sequencing for diagnostic purposes [...].
Collapse
Affiliation(s)
- Miles D Thompson
- Krembil Brain Institute, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada
| |
Collapse
|
2
|
Thompson MD, Knaus A. Rare Genetic Developmental Disabilities: Mabry Syndrome (MIM 239300) Index Cases and Glycophosphatidylinositol (GPI) Disorders. Genes (Basel) 2024; 15:619. [PMID: 38790248 PMCID: PMC11121671 DOI: 10.3390/genes15050619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The case report by Mabry et al. (1970) of a family with four children with elevated tissue non-specific alkaline phosphatase, seizures and profound developmental disability, became the basis for phenotyping children with the features that became known as Mabry syndrome. Aside from improvements in the services available to patients and families, however, the diagnosis and treatment of this, and many other developmental disabilities, did not change significantly until the advent of massively parallel sequencing. As more patients with features of the Mabry syndrome were identified, exome and genome sequencing were used to identify the glycophosphatidylinositol (GPI) biosynthesis disorders (GPIBDs) as a group of congenital disorders of glycosylation (CDG). Biallelic variants of the phosphatidylinositol glycan (PIG) biosynthesis, type V (PIGV) gene identified in Mabry syndrome became evidence of the first in a phenotypic series that is numbered HPMRS1-6 in the order of discovery. HPMRS1 [MIM: 239300] is the phenotype resulting from inheritance of biallelic PIGV variants. Similarly, HPMRS2 (MIM 614749), HPMRS5 (MIM 616025) and HPMRS6 (MIM 616809) result from disruption of the PIGO, PIGW and PIGY genes expressed in the endoplasmic reticulum. By contrast, HPMRS3 (MIM 614207) and HPMRS4 (MIM 615716) result from disruption of post attachment to proteins PGAP2 (HPMRS3) and PGAP3 (HPMRS4). The GPI biosynthesis disorders (GPIBDs) are currently numbered GPIBD1-21. Working with Dr. Mabry, in 2020, we were able to use improved laboratory diagnostics to complete the molecular diagnosis of patients he had originally described in 1970. We identified biallelic variants of the PGAP2 gene in the first reported HPMRS patients. We discuss the longevity of the Mabry syndrome index patients in the context of the utility of pyridoxine treatment of seizures and evidence for putative glycolipid storage in patients with HPMRS3. From the perspective of the laboratory innovations made that enabled the identification of the HPMRS phenotype in Dr. Mabry's patients, the need for treatment innovations that will benefit patients and families affected by developmental disabilities is clear.
Collapse
Affiliation(s)
- Miles D. Thompson
- Krembil Brain Institute, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany;
| |
Collapse
|
3
|
Obaid O, Batawi R, Alqurashi H, Ewis T, Obaid AA. Bilateral Glaucoma as Possible Additional Feature for PGAP3-Associated Hyperphosphatasia. Case Rep Genet 2024; 2024:3561555. [PMID: 38558875 PMCID: PMC10981546 DOI: 10.1155/2024/3561555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 02/18/2024] [Accepted: 03/02/2024] [Indexed: 04/04/2024] Open
Abstract
Hyperphosphatasia with mental disorder (HPMRS) is a rare autosomal recessive disease caused by gene mutations in enzymes involved in the synthesis and remodeling of lipids. Seven-month-old boy diagnosed with bilateral glaucoma had a cleft palate, facial dysmorphism, hypertelorism, a broad nasal bridge, and large fleshy earlobes. A brain MRI scan also revealed brain abnormalities. The observed phenotype in a seven-month-old boy is in agreement with the phenotypic features of HPRMS type-4. Whole exome sequencing revealed a possible pathogenic variant of PGAP3 in a homozygous state (c.320C > T, p.Ser107Leu) which supported the diagnosis of HPRMS type-4. We report an unusual presentation for HPMRS and suggest adding this syndrome to the list of differential diagnoses of syndromic congenital glaucoma.
Collapse
Affiliation(s)
- Osama Obaid
- Department of Pediatrics, Maternity and Children Hospital, Makkah, Saudi Arabia
| | - Reem Batawi
- Department of Pediatrics, Maternity and Children Hospital, Makkah, Saudi Arabia
| | - Heba Alqurashi
- Department of Pediatrics, Maternity and Children Hospital, Makkah, Saudi Arabia
| | - Thana Ewis
- Department of Radiology, Maternity and Children Hospital, Makkah, Saudi Arabia
| | - Ahmad A. Obaid
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al Qura University, Makkah, Saudi Arabia
| |
Collapse
|
4
|
Hutny M, Lipinski P, Jezela-Stanek A. Characteristics of Neuroimaging and Behavioural Phenotype in Polish Patients with PIGV-CDG-An Observational Study and Literature Review. Genes (Basel) 2023; 14:1208. [PMID: 37372388 DOI: 10.3390/genes14061208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Congenital disorders of glycosylation (CDGs) are a wide group of genetic diseases characterised by a severe clinical spectrum, consisting of developmental delays, dysmorphisms, and neurological deficits. Mutations in the PIGV gene lead to a disorder called hyperphosphatasia with impaired intellectual development syndrome 1 (HPMRS1), distinct from other CDGs in terms of hyperphosphatemia related to abnormal ALP activity and brachytelephalangy. This article discusses the phenotype of six Polish patients with HPMRS1 with a special focus on behavioural and imaging features, which were not addressed in 26 previously reported cases. The medical records of six patients aged 6 to 22 years were collected and analysed. In all cases, the same PIGV homozygotic mutation (c.1022C>A; p.Ala341Glu) was found, although the patients presented a diverse spectrum of neurological and developmental disorders, concerning in most cases the muscular tonus and general developmental delay. The most prevalent dysmorphic features included hypertelorism, high palate, and finger anomalies, whereas other characteristics present in all previously described cases, such as a short, broad nose and brachytelephalangy, were less frequently observed. Similarly to previous reports, the magnetic resonance (MR) and computed tomography (CT) head scans returned varied results, including physiological and pathological brain images in equal measure, the latter of which consisted of cortical atrophy, delayed myelination, hydrocephalus, and hypoplastic corpus callosum. Each patient exhibited symptoms characteristic of autism spectrum disorders, especially in terms of attention deficits, as well as controlling and expressing emotions. The most common type of sensory processing disorder was over-responsivity. Despite the low prevalence of HPMRS1, the patients reported in the literature presented a rather uniform phenotype, which does not correspond with the one found in each individual of the studied group. Behavioural disorders and sensory impairment require additional care and awareness considering the global developmental delay often observed in these patients.
Collapse
Affiliation(s)
- Michal Hutny
- Students' Scientific Society, Department of Paediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, 40-752 Katowice, Poland
| | - Patryk Lipinski
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, 04-730 Warsaw, Poland
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland
| |
Collapse
|
5
|
Riva A, D'Onofrio G, Pisati A, Roberti R, Amadori E, Bosch F, de Souza CFM, Thomas A, Russo E, Striano P, Bayat A. Cannabidiol Add-On in Glycosylphosphatidylinositol-Related Drug-Resistant Epilepsy. Cannabis Cannabinoid Res 2023. [PMID: 36862522 DOI: 10.1089/can.2022.0255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
Background: Glycosylphosphatidylinositol-anchored protein deficiencies (GPI-ADs) are commonly associated with drug-resistant epilepsy (DRE). Cannabidiol (CBD) is approved for the adjunctive treatment of seizures in Dravet/Lennox-Gastaut Syndromes and Tuberous Sclerosis Complex. We report on the efficacy and safety of CBD for the treatment of DRE in patients with genetically proven GPI-AD. Patients and Methods: Patients received add-on treatment with purified GW-pharma CBD (Epidyolex®). Efficacy endpoints were the percentage of patients with ≥50% (responders) or >25<50% (partial responders) reduction in monthly seizures from baseline and at 12 (M12) months of follow-up. Safety was evaluated through adverse events (AEs) monitoring. Results: Six patients (5 males) were enrolled. The median age at seizures onset was 5 months and the syndromic diagnosis was early infantile developmental and epileptic encephalopathy in 4 patients and focal non-lesional epilepsy or GEFS+ in one patient each. Five out of six (83%) patients were responders at M12, while one was a partial responder. No severe AEs were reported. Mean prescribed CBD dose was 17.85 mg/kg/day and median treatment duration is currently 27 months. Conclusions: In summary, off-label treatment with CBD was effective and safe in patients with DRE due to GPI-ADs.
Collapse
Affiliation(s)
- Antonella Riva
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini," Genoa, Italy
| | - Gianluca D'Onofrio
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini," Genoa, Italy
| | - Angelica Pisati
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini," Genoa, Italy
| | - Roberta Roberti
- Department of Science of Health, School of Medicine, University of Catanzaro, Catanzaro, Italy
| | - Elisabetta Amadori
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini," Genoa, Italy
| | | | | | | | - Emilio Russo
- Department of Science of Health, School of Medicine, University of Catanzaro, Catanzaro, Italy
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini," Genoa, Italy
| | - Allan Bayat
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
6
|
Thompson MD, Li X, Spencer-Manzon M, Andrade DM, Murakami Y, Kinoshita T, Carpenter TO. Excluding Digenic Inheritance of PGAP2 and PGAP3 Variants in Mabry Syndrome (OMIM 239300) Patient: Phenotypic Spectrum Associated with PGAP2 Gene Variants in Hyperphosphatasia with Mental Retardation Syndrome-3 (HPMRS3). Genes (Basel) 2023; 14:genes14020359. [PMID: 36833286 PMCID: PMC9957281 DOI: 10.3390/genes14020359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
We present a case report of a child with features of hyperphosphatasia with neurologic deficit (HPMRS) or Mabry syndrome (MIM 239300) with variants of unknown significance in two post-GPI attachments to proteins genes, PGAP2 and PGAP3, that underlie HPMRS 3 and 4. BACKGROUND In addition to HPMRS 3 and 4, disruption of four phosphatidylinositol glycan (PIG) biosynthesis genes, PIGV, PIGO, PIGW and PIGY, result in HPMRS 1, 2, 5 and 6, respectively. METHODS Targeted exome panel sequencing identified homozygous variants of unknown significance (VUS) in PGAP2 c:284A>G and PGAP3 c:259G>A. To assay the pathogenicity of these variants, we conducted a rescue assay in PGAP2 and PGAP3 deficient CHO cell lines. RESULTS Using a strong (pME) promoter, the PGAP2 variant did not rescue activity in CHO cells and the protein was not detected. Flow cytometric analysis showed that CD59 and CD55 expression on the PGAP2 deficient cell line was not restored by variant PGAP2. By contrast, activity of the PGAP3 variant was similar to wild-type. CONCLUSIONS For this patient with Mabry syndrome, the phenotype is likely to be predominantly HPMRS3: resulting from autosomal recessive inheritance of NM_001256240.2 PGAP2 c:284A>G, p.Tyr95Cys. We discuss strategies for establishing evidence for putative digenic inheritance in GPI deficiency disorders.
Collapse
Affiliation(s)
- Miles D. Thompson
- Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, Krembil Brain Institute, Toronto, ON M5T, Canada
- Correspondence: (M.D.T.); (T.O.C.)
| | - Xueying Li
- Osaka University, 3-1 Yamada-Oka, Osaka 565-0871, Japan
| | | | - Danielle M. Andrade
- Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, Krembil Brain Institute, Toronto, ON M5T, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S, Canada
| | | | | | - Thomas O. Carpenter
- Yale Pediatrics (Endocrinology), Yale University School of Medicine, New Haven, CT 06521, USA
- Correspondence: (M.D.T.); (T.O.C.)
| |
Collapse
|
7
|
Messina M, Manea E, Cullup T, Tuschl K, Batzios S. Hyperphosphatasia with mental retardation syndrome 3: Cerebrospinal fluid abnormalities and correction with pyridoxine and Folinic acid. JIMD Rep 2023; 64:42-52. [PMID: 36636587 PMCID: PMC9830023 DOI: 10.1002/jmd2.12347] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/16/2022] [Accepted: 10/25/2022] [Indexed: 11/24/2022] Open
Abstract
Glycosylphosphatidylinositol anchored proteins (GPI-APs) represent a class of molecules attached to the external leaflet of the plasma membrane by the GPI anchor where they play important roles in numerous cellular processes including neurogenesis, cell adhesion, immune response and signalling. Within the group of GPI anchor defects, six present with the clinical phenotype of Hyperphosphatasia with Mental Retardation Syndrome (HPMRS, Mabry Syndrome) characterized by moderate to severe intellectual disability, dysmorphic features, hypotonia, seizures and persistent hyperphosphatasia. We report the case of a 5-year-old female with global developmental delay associated with precocious puberty and persistently raised plasma alkaline phosphatase. Targeted next generation sequencing analysis of the HPMRS genes identified novel compound heterozygous variants in the PGAP2 gene (c.103del p.(Leu35Serfs*90)and c.134A > Gp.(His45Arg)) consistent with the diagnosis of HPMRS type 3. Cerebrospinal fluid (CSF) neurotransmitter analysis showed low levels of pyridoxal phosphate and 5-methyltetrahydrofolate and raised homovanillic acid. Supplementation with pyridoxine and folinic acid led to normalization of biochemical abnormalities. The patient continues to make developmental progress with significant improvement in speech and fine motor skills. Our reported case expands the clinical spectrum of HPMRS3 in which multisystem involvement is being increasingly recognized. Furthermore, it shows that miss-targeting GPI-APs and the effect on normal cellular function could provide a physiopathologic explanation for the CSF biochemical abnormalities with management implications for a group of disorders that currently has no treatment that can lead possibly to improved clinical outcomes.
Collapse
Affiliation(s)
- Martina Messina
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
| | - Emanuela Manea
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
| | - Thomas Cullup
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for ChildrenLondonUK
| | - Karin Tuschl
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
- University College London Great Ormond Street Institute for ChildrenLondonUK
| | - Spyros Batzios
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
| |
Collapse
|
8
|
Ronzoni L, Boito S, Meossi C, Cesaretti C, Rinaldi B, Agolini E, Rizzuti T, Pezzoli L, Silipigni R, Novelli A, Iascone M, Persico N, Natacci F. Prenatal ultrasound findings associated with PIGW variants: One more piece in the FRYNS syndrome puzzle? PIGW-related prenatal findings. Prenat Diagn 2022; 42:1493-1502. [PMID: 35788948 DOI: 10.1002/pd.6204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/15/2022] [Accepted: 06/27/2022] [Indexed: 01/27/2023]
Abstract
OBJECTIVE We describe the prenatal ultrasound findings and autopsy of three fetuses with multiple congenital anomalies (MCA) whose diagnostic workup suggested the same genetic etiology. We conducted a literature review to corroborate the molecular results and find evidence that the identified variants are responsible for the phenotype seen. METHODS Trio-based Exome Sequencing (ES) analysis was performed on chorionic villus samples. We reviewed available reports dealing with prenatal manifestations of genes involved in the Glycosylphosphatidylinositols (GPI) biosynthesis defects (GPIBDs). RESULTS Prenatal findings shared by all the three pregnancies included facial dysmorphisms, brain malformations of the posterior fossa, skeletal and genitourinary anomalies. ES analysis identified homozygous variants of uncertain significance in PIGW in the three fetuses. Prenatal findings of the three pregnancies overlapped with those previously described for PIGW variants and with those associated with PIGN, PIGV and PIGA variants. CONCLUSION Based on the phenotypic overlap between the prenatal findings in our three cases and other cases with pathogenic variants in other genes involved in GPIBDs, we speculate that the variants identified in the three fetuses are likely causal of their phenotype and that the PIGWclinical spectrum might extend to MCA, mainly involving brain, skeletal and genitourinary systems. Moreover, we suggest that also PIGW could be involved in Fryns/Fryns-like phenotypes.
Collapse
Affiliation(s)
- Luisa Ronzoni
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Policlinico di Milano, Milan, Italy
| | - Simona Boito
- Fetal Medicine and Surgery Service, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Camilla Meossi
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Policlinico di Milano, Milan, Italy
| | - Claudia Cesaretti
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Policlinico di Milano, Milan, Italy
| | - Berardo Rinaldi
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Policlinico di Milano, Milan, Italy
| | - Emanuele Agolini
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Tommaso Rizzuti
- Division of Pathology, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Laura Pezzoli
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Rosamaria Silipigni
- Laboratory of Medical Genetics, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Iascone
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Nicola Persico
- Fetal Medicine and Surgery Service, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Federica Natacci
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Policlinico di Milano, Milan, Italy
| |
Collapse
|
9
|
Tanigawa J, Nabatame S, Tominaga K, Nishimura Y, Maegaki Y, Kinosita T, Murakami Y, Ozono K. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021; 43:680-687. [PMID: 33824024 DOI: 10.1016/j.braindev.2021.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/21/2021] [Accepted: 02/28/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We aimed to assess the efficacy and safety of high-dose pyridoxine treatment for seizures and its effects on development in patients with inherited glycosylphosphatidylinositol deficiencies (IGDs). METHODS In this prospective open-label multicenter pilot study, we enrolled patients diagnosed with IGDs using flow cytometry and/or genetic tests. The patients received oral pyridoxine (20-30 mg/kg/day) for 1 year, in addition to previous treatment. RESULTS All nine enrolled patients (mean age: 66.3 ± 44.3 months) exhibited marked decreases in levels of CD16, a glycosylphosphatidylinositol-anchored protein, on blood granulocytes. The underlying genetic causes of IGDs were PIGO, PIGL, and unknown gene mutations in two, two, and five patients, respectively. Six patients experienced seizures, while all patients presented with developmental delay (mean developmental age: 11.1 ± 8.1 months). Seizure frequencies were markedly (>50%) and drastically (>90%) reduced in three and one patients who experienced seizures, respectively. None of the patients presented with seizure exacerbation. Eight of nine patients exhibited modest improvements in development (P = 0.14). No adverse events were observed except for mild transient diarrhea in one patient. CONCLUSION One year of daily high-dose pyridoxine treatment was effective in the treatment of seizures in more than half of our patients with IGDs and modestly improved development in the majority of them. Moreover, such treatment was reasonably safe. These findings indicate that high-dose pyridoxine treatment may be effective against seizures in patients with IGDs, although further studies are required to confirm our findings. (University Hospital Medical Information Network Clinical Trials Registry [UMIN-CTR] number: UMIN000024185.).
Collapse
Affiliation(s)
- Junpei Tanigawa
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shin Nabatame
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Koji Tominaga
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Division of Developmental Neuroscience, United Graduate School of Child Development, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoko Nishimura
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Yoshihiro Maegaki
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Taroh Kinosita
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
10
|
Okuda T, Yonekawa T, Murakami Y, Kinoshita T, Ito T, Matsushita K, Koike Y, Inoue M, Uchida K, Yodoya N, Ohashi H, Sawada H, Iwamoto S, Mitani Y, Hirayama M.
PIGO
variants in a boy with features of Mabry syndrome who also exhibits Fryns syndrome with peripheral neuropathy. Am J Med Genet A 2021. [DOI: 10.1002/ajmg.a.62005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Taro Okuda
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Takahiro Yonekawa
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center Osaka University Osaka Japan
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center Osaka University Osaka Japan
| | - Takahiro Ito
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Kohei Matsushita
- Department of Gastrointestinal and Pediatric Surgery Mie University Graduate School of Medicine Tsu Mie Japan
| | - Yuhki Koike
- Department of Gastrointestinal and Pediatric Surgery Mie University Graduate School of Medicine Tsu Mie Japan
| | - Mikihiro Inoue
- Department of Gastrointestinal and Pediatric Surgery Mie University Graduate School of Medicine Tsu Mie Japan
| | - Keiichi Uchida
- Department of Gastrointestinal and Pediatric Surgery Mie University Graduate School of Medicine Tsu Mie Japan
| | - Noriko Yodoya
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Hiroyuki Ohashi
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Hirofumi Sawada
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Shotaro Iwamoto
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Yoshihide Mitani
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| | - Masahiro Hirayama
- Department of Pediatrics Mie University Graduate School of Medicine Tsu Mie Japan
| |
Collapse
|
11
|
Whyte MP, Ma NS, Mumm S, Gottesman GS, McAlister WH, Nenninger AR, Bijanki VN, Ericson KL, Magnusson P. Persistent idiopathic hyperphosphatasemia from bone alkaline phosphatase in a healthy boy. Bone 2020; 138:115459. [PMID: 32474245 DOI: 10.1016/j.bone.2020.115459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 11/19/2022]
Abstract
Alkaline phosphatase (ALP) in humans comprises a family of four cell-surface phosphomonoester phosphohydrolase isozymes. Three genes separately encode the "tissue-specific" ALPs whereas the fourth gene encodes ubiquitous homodimeric "tissue-nonspecific" ALP (TNSALP) richly expressed in bone, liver, kidney, and developing teeth. TNSALP monomers have five putative N-linked glycosylation sites where different post-translational modifications account for this isozyme's distinctive physicochemical properties in different organs. Three bone-derived TNSALP (BALP) isoforms (B/I, B1, and B2) are present in healthy serum, whereas a fourth BALP isoform (B1x) can circulate in chronic kidney disease. Herein, we report a healthy boy with persistent hyperphosphatasemia due to BALP levels two- to threefold higher than age-appropriate reference values. High-performance liquid chromatography, electrophoresis, heat inactivation, catalysis inhibition, and polyethylene glycol precipitation revealed increased serum B/I, B1, and B2 differing from patterns found in skeletal diseases. B/I was ~23-fold elevated. Absence of mental retardation and physical stigmata excluded Mabry syndrome, the ALP-anchoring disorder causing hyperphosphatasemia. Routine biochemical studies indicated intact mineral homeostasis. Serum N-terminal propeptide of type I procollagen (P1NP) level was normal, but C-terminal cross-linking telopeptide of type I collagen (CTX) level was elevated. However, radiological studies showed no evidence for a generalized skeletal disturbance. Circulating pyridoxal 5'-phosphate, a TNSALP natural substrate, was not low despite the laboratory hyperphosphatasemia, thereby suggesting BALP phosphohydrolase activity was not elevated endogenously. Mutation analysis of the ALPL gene encoding TNSALP revealed no defect. His non-consanguineous healthy parents had serum total ALP activity and BALP protein levels that were normal. Our patient's sporadic idiopathic hyperphosphatasemia could reflect altered post-translational modification together with increased expression and/or impaired degradation of BALP.
Collapse
Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Nina S Ma
- Division of Endocrinology, Boston Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
| | - Steven Mumm
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO 63110, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO 63110, USA.
| | - Gary S Gottesman
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO 63110, USA.
| | - William H McAlister
- Mallinckrodt Institute of Radiology, Washington University School of Medicine at St. Louis Children's Hospital, St. Louis, MO 63110, USA.
| | - Angela R Nenninger
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO 63110, USA.
| | - Vinieth N Bijanki
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children, St. Louis, MO 63110, USA.
| | - Karen L Ericson
- Department of Chemistry, Purdue University-Fort Wayne, Fort Wayne, IN 46805, USA.
| | - Per Magnusson
- Department of Clinical Chemistry and Department of Biomedical and Clinical Sciences, Linköping University, SE-58185 Linköping, Sweden.
| |
Collapse
|
12
|
Thompson MD, Knaus AA, Barshop BA, Caliebe A, Muhle H, Nguyen TTM, Baratang NV, Kinoshita T, Percy ME, Campeau PM, Murakami Y, Cole DE, Krawitz PM, Mabry CC. A post glycosylphosphatidylinositol (GPI) attachment to proteins, type 2 (PGAP2) variant identified in Mabry syndrome index cases: Molecular genetics of the prototypical inherited GPI disorder. Eur J Med Genet 2019; 63:103822. [PMID: 31805394 DOI: 10.1016/j.ejmg.2019.103822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/12/2019] [Accepted: 11/30/2019] [Indexed: 10/25/2022]
Abstract
We report that recessive inheritance of a post-GPI attachment to proteins 2 (PGAP2) gene variant results in the hyperphosphatasia with neurologic deficit (HPMRS) phenotype described by Mabry et al., in 1970. HPMRS, or Mabry syndrome, is now known to be one of 21 inherited glycosylphosphatidylinositol (GPI) deficiencies (IGDs), or GPI biosynthesis defects (GPIBDs). Bi-allelic mutations in at least six genes result in HPMRS phenotypes. Disruption of four phosphatidylinositol glycan (PIG) biosynthesis genes, PIGV, PIGO, PIGW and PIGY, expressed in the endoplasmic reticulum, result in HPMRS 1, 2, 5 and 6; disruption of the PGAP2 and PGAP3 genes, necessary for stabilizing the association of GPI anchored proteins (AP) with the Golgi membrane, result in HPMRS 3 and 4. We used exome sequencing to identify a novel homozygous missense PGAP2 variant NM_014489.3:c.881C > T, p.Thr294Met in two index patients and targeted sequencing to identify this variant in an unrelated patient. Rescue assays were conducted in two PGAP2 deficient cell lines, PGAP2 KO cells generated by CRISPR/Cas9 and PGAP2 deficient CHO cells, in order to examine the pathogenicity of the PGAP2 variant. First, we used the CHO rescue assay to establish that the wild type PGAP2 isoform 1, translated from transcript 1, is less active than the wild type PGAP2 isoform 8, translated from transcript 12 (alternatively spliced to omit exon 3). As a result, in our variant rescue assays, we used the more active NM_001256240.2:c.698C > T, p.Thr233Met isoform 8 instead of NM_014489.3:c.881C > T, p.Thr294Met isoform 1. Flow cytometric analysis showed that restoration of cell surface CD59 and CD55 with variant PGAP2 isoform 8, driven by the weak (pTA FLAG) promoter, was less efficient than wild type isoform 8. Therefore, we conclude that recessive inheritance of c.881C > T PGAP2, expressed as the hypomorphic PGAP2 c.698C > T, p.Thr233Met isoform 8, results in prototypical Mabry phenotype, HPMRS3 (GPIBD 8 [MIM: 614207]). This study highlights the need for long-term follow up of individuals with rare diseases in order to ensure that they benefit from innovations in diagnosis and treatment.
Collapse
Affiliation(s)
- Miles D Thompson
- Department of Pediatrics, UCSD School of Medicine, United States.
| | - Alexej A Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany
| | - Bruce A Barshop
- Department of Pediatrics, UCSD School of Medicine, United States
| | - Almuth Caliebe
- Department of Human Genetics, University Hospital Schleswig-Holstein, Campus Kiel, Christian-Albrechts-University, Kiel, Germany
| | - Hiltrud Muhle
- Department of Human Genetics, University Hospital Schleswig-Holstein, Campus Kiel, Christian-Albrechts-University, Kiel, Germany
| | - Thi Tuyet Mai Nguyen
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Canada
| | - Nissan V Baratang
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Canada
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases, Osaka University, Japan
| | - Maire E Percy
- Department of Physiology, University of Toronto, Canada; Department of Obstetrics and Gynaecology, University of Toronto, Canada
| | - Philippe M Campeau
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Canada
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases, Osaka University, Japan
| | - David E Cole
- Laboratory Medicine and Pathobiology, University of Toronto, Canada
| | - Peter M Krawitz
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany
| | - C Charlton Mabry
- Department of Pediatrics, College of Medicine, University of Kentucky, United States
| |
Collapse
|
13
|
Abstract
Introduction: Vitamin B6 dependent epilepsies are a group of treatable diseases (ALDH7A1 deficiency, PNPO deficiency, PLP binding protein deficiency, hyperprolinaemia type II and hypophosphatasia and glycosylphosphatidylinositol anchor synthesis defects) responding to pyridoxine or pyridoxal-5I-phosphate. Areas covered: A critical review was conducted on the therapeutic management of all the reported patients with genetically confirmed diagnoses of diseases affecting vitamin B6 metabolism and presenting with pyridoxine or pyridoxal-5I-phosphate dependent-seizures. Data about safety and efficacy were analyzed as well as the management of supplementation with pyridoxine or pyridoxal-5I-phosphate both in the acute phases and in the maintenance therapies. The authors also analyzed alternative therapeutic strategies for ALDH7A1 deficiency (lysine-restricted diet, arginine supplementation, oligonucleotide antisense therapy, upstream inhibition of aminoadipic semialdehyde synthase). Expert opinion: The administration of pyridoxine or pyridoxal-5I-phosphate should be considered in all intractable seizures also beyond the first year of life. Lysine restricted diet and arginine supplementation should be introduced in all the confirmed ALDH7A1 deficient patients. Pre or post-natal supplementation with pyridoxine should be given in familial cases until an eventual molecular genetic disconfirmation. Minor data about alternative therapies are available for other disorders of vitamin B6 metabolism.
Collapse
Affiliation(s)
- Mario Mastrangelo
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome , Roma , Italy
| | - Serena Cesario
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome , Roma , Italy
| |
Collapse
|
14
|
Nicklas JA, Vacek PM, Carter EW, McDiarmid M, Albertini RJ. Molecular analysis of glycosylphosphatidylinositol anchor deficient aerolysin resistant isolates in gulf war i veterans exposed to depleted uranium. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:470-493. [PMID: 30848503 DOI: 10.1002/em.22283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
During the First Gulf War (1991) over 100 servicemen sustained depleted uranium (DU) exposure through wound contamination, inhalation, and shrapnel. The Department of Veterans Affairs has a surveillance program for these Veterans which has included genotoxicity assays. The frequencies of glycosylphosphatidylinositol anchor (GPIa) negative (aerolysin resistant) cells determined by cloning assays for these Veterans are reported in Albertini RJ et al. (2019: Environ Mol Mutagen). Molecular analyses of the GPIa biosynthesis class A (PIGA) gene was performed on 862 aerolysin-resistant T-lymphocyte recovered isolates. The frequencies of different types of PIGA mutations were compared between high and low DU exposure groups. Additional molecular studies were performed on mutants that produced no PIGA mRNA or with deletions of all or part of the PIGA gene to determine deletion size and breakpoint sequence. One mutant appeared to be the result of a chromothriptic event. A significant percentage (>30%) of the aerolysin resistant isolates, which varied by sample year and Veteran, had wild-type PIGA cDNA (no mutation). As described in Albertini RJ et al. (2019: Environ Mol Mutagen), TCR gene rearrangement analysis of these isolates indicated most arose from multiple T-cell progenitors (hence the inability to find a mutation). It is likely that these isolates were the result of failure of complete selection against nonmutant cells in the cloning assays. Real-time studies of GPIa resistant isolates with no PIGA mutation but with a single TCR gene rearrangement found one clone with a PIGV deletion and several others with decreased levels of GPIa pathway gene mRNAs implying mutation in other GPIa pathway genes. Environ. Mol. Mutagen. 60:470-493, 2019. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Janice A Nicklas
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont
| | - Pamela M Vacek
- Medical Biostatistics Unit, University of Vermont College of Medicine, Burlington, Vermont
| | - Elizabeth W Carter
- Jeffords Institute for Quality, University of Vermont Medical Center, Burlington, Vermont
| | - Melissa McDiarmid
- Occupational Health Program, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
- U.S. Department of Veterans Affairs, Washington, District of Columbia
| | - Richard J Albertini
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont
| |
Collapse
|
15
|
Albertini RJ, Nicklas JA, Vacek PM, Carter EW, McDiarmid M. Longitudinal study of t-cell somatic mutations conferring glycosylphosphatidylinositol-anchor deficiency in gulf war I veterans exposed to depleted uranium. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:494-504. [PMID: 30848527 DOI: 10.1002/em.22281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
Fifty Veterans of the first Gulf War in 1991 exposed to depleted uranium (DU) were studied for glycosylphosphatidylinositol-anchor (GPIa) deficient T-cell mutants on three occasions during the years 2009, 2011, and 2013. GPIa deficiency was determined in two ways: cloning assays employing aerolysin selection and cytometry using the FLAER reagent for positive staining of GPIa cell surface proteins. Subsequent molecular analyses of deficient isolates recovered from cloning assays (Nicklas JA et al. [2019]: Environ Mol Mutagen) revealed apparent incomplete selection in some cloning assays, necessitating correction of original data to afford a more realistic estimate of GPIa deficient mutant frequency (MF) values. GPIa deficient variant frequencies (VFs) determined by cytometry were determined in the years 2011 and 2013. A positive but nonsignificant association was observed between MF and VF values determined on the same blood samples during 2013. Exposure to DU had no effect on either GPIa deficient MF or VFs. Environ. Mol. Mutagen. 60:494-504, 2019. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Richard J Albertini
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont
| | - Janice A Nicklas
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont
| | - Pamela M Vacek
- Medical Biostatistics Unit, University of Vermont College of Medicine, Burlington, Vermont
| | - Elizabeth W Carter
- Jeffords Institute for Quality, University of Vermont Medical Center, Burlington, Vermont
| | - Melissa McDiarmid
- Occupational Health Program, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
- U.S. Department of Veterans Affairs, Washington, DC
| |
Collapse
|
16
|
Balobaid A, Ben-Omran T, Ramzan K, Altassan R, Almureikhi M, Musa S, Al-Hashmi N, Al-Owain M, Al-Zaidan H, Al-Hassnan Z, Imtiaz F, Al-Sayed M. Delineating the phenotypic spectrum of hyperphosphatasia with mental retardation syndrome 4 in 14 patients of Middle-Eastern origin. Am J Med Genet A 2018; 176:2850-2857. [PMID: 30345601 DOI: 10.1002/ajmg.a.40627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/13/2018] [Accepted: 08/13/2018] [Indexed: 12/31/2022]
Abstract
Hyperphosphatasia with mental retardation syndrome 4 (HPMRS4) is a rare autosomal recessive condition caused by an impairment of glycosylphophatidylinositol biosynthesis. The cardinal features of HPMRS4 include; characteristic facial features, severe intellectual disability and various neurologic abnormalities. We report here detailed clinical, biochemical, and molecular findings of 14 patients clinically suspected to have HPMRS4, from three Middle-Eastern Countries; Saudi Arabia, Qatar, and Oman. All patients in our series presented with the cardinal features pointing to HPMRS4 and with an elevated alkaline phosphatase level. Five patients had megalocornea, which have been reported recently in an Arab patient. Additionally, fracture, bilateral coxa valga, camptodactyly, truncal obesity, and hyperpigmented macules of the upper thigh, each was seen once and was not described before with HPMRS4. Additional clinical and radiological findings are described, supporting the novel clinical and radiological findings recently described in Egyptian patients. The utilization of homozygosity mapping coupled with PGAP3 sequencing and whole exome sequencing facilitated the mutation detection in these patients. These missense mutations include c.320C > T (p.S107 L), c.850C > T (p.H284Y), and c.851A > G (p.H284R) in the PGAP3 gene. We believe that the recurrent mutations identified in our cohort may represent founder mutations in big tribes from a certain geographical region of Saudi Arabia, Qatar, and Oman. Therefore, in case of a clinical suspicion of HPMRS4 in these populations, targeted genetic testing for the identified mutations should be performed first to expedite the genetic diagnosis.
Collapse
Affiliation(s)
- Ameera Balobaid
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Tawfeg Ben-Omran
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Qatar
| | - Khushnooda Ramzan
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Ruqaiah Altassan
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Mariam Almureikhi
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Qatar
| | - Sara Musa
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Qatar
| | | | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hamad Al-Zaidan
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Zuhair Al-Hassnan
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Faiqa Imtiaz
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Moeenaldeen Al-Sayed
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| |
Collapse
|
17
|
Nguyen TTM, Murakami Y, Wigby KM, Baratang NV, Rousseau J, St-Denis A, Rosenfeld JA, Laniewski SC, Jones J, Iglesias AD, Jones MC, Masser-Frye D, Scheuerle AE, Perry DL, Taft RJ, Le Deist F, Thompson M, Kinoshita T, Campeau PM. Mutations in PIGS, Encoding a GPI Transamidase, Cause a Neurological Syndrome Ranging from Fetal Akinesia to Epileptic Encephalopathy. Am J Hum Genet 2018; 103:602-611. [PMID: 30269814 DOI: 10.1016/j.ajhg.2018.08.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/23/2018] [Indexed: 11/17/2022] Open
Abstract
Inherited GPI deficiencies (IGDs) are a subset of congenital disorders of glycosylation that are increasingly recognized as a result of advances in whole-exome sequencing (WES) and whole-genome sequencing (WGS). IGDs cause a series of overlapping phenotypes consisting of seizures, dysmorphic features, multiple congenital malformations, and severe intellectual disability. We present a study of six individuals from three unrelated families in which WES or WGS identified bi-allelic phosphatidylinositol glycan class S (PIGS) biosynthesis mutations. Phenotypes included severe global developmental delay, seizures (partly responding to pyridoxine), hypotonia, weakness, ataxia, and dysmorphic facial features. Two of them had compound-heterozygous variants c.108G>A (p.Trp36∗) and c.101T>C (p.Leu34Pro), and two siblings of another family were homozygous for a deletion and insertion leading to p.Thr439_Lys451delinsArgLeuLeu. The third family had two fetuses with multiple joint contractures consistent with fetal akinesia. They were compound heterozygous for c.923A>G (p.Glu308Gly) and c.468+1G>C, a splicing mutation. Flow-cytometry analyses demonstrated that the individuals with PIGS mutations show a GPI-AP deficiency profile. Expression of the p.Trp36∗ variant in PIGS-deficient HEK293 cells revealed only partial restoration of cell-surface GPI-APs. In terms of both biochemistry and phenotype, loss of function of PIGS shares features with PIGT deficiency and other IGDs. This study contributes to the understanding of the GPI-AP biosynthesis pathway by describing the consequences of PIGS disruption in humans and extending the family of IGDs.
Collapse
Affiliation(s)
- Thi Tuyet Mai Nguyen
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Kristen M Wigby
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92093, USA
| | - Nissan V Baratang
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada
| | - Justine Rousseau
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada
| | - Anik St-Denis
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada
| | - Jill A Rosenfeld
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Julie Jones
- Greenwood Genetic Center, Greenwood, SC 29646, USA
| | - Alejandro D Iglesias
- NewYork-Presbyterian Morgan Stanley Children's Hospital, New York, NY 10032, USA
| | - Marilyn C Jones
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92093, USA
| | | | | | | | | | - Françoise Le Deist
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada
| | - Miles Thompson
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92093, USA
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Philippe M Campeau
- Centre Hospitalier Universitaire Sainte Justine Research Center, University of Montreal, Montreal, QC H3T1C5, Canada.
| |
Collapse
|
18
|
Hyperphosphatasia with mental retardation syndrome type 4 In two siblings-expanding the phenotypic and mutational spectrum. Eur J Med Genet 2018; 62:103535. [PMID: 30217754 DOI: 10.1016/j.ejmg.2018.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/31/2018] [Accepted: 09/09/2018] [Indexed: 11/20/2022]
Abstract
Hyperphosphatasia with mental retardation syndrome (HPMRS) (OMIM # 239300), is an autosomal recessive disease with phenotypic variability, ranging from mild nonsyndromic intellectual disability to syndromic form with severe intellectual disability, seizures, elevated alkaline phosphatase, brachytelephalangy and facial dysmorphism, Six subgroups of HPMRS were defined in which pathogenic mutations affect genes involved in either synthesis or remodeling of the anchor proteins. Among these, PGAP3 mutations are associated with HPMRS type 4. We report two siblings with a novel homozygous variant in PGAP3 expanding both the phenotypic findings and the mutational spectrum of HPMRS type 4. Developmental delay, hypotonia, facial dysmorphism were the consistent findings with HPMRS in our patients. Large anterior fontanel size, gum hypertrophy, pes equinovarus, concentric ventricle hypertrophy, frontoparietal atrophy and dysphagia were the findings of our patients that have been reported for the first time in this syndrome. Although there is an extensive list of differential diagnoses in patients with developmental delay and hypotonia, the recognizable pattern of facial features, parental consanguinity and mild to moderate serum ALP elevation should be sufficiently suggestive of HPMRS type 4.
Collapse
|
19
|
Knaus A, Pantel JT, Pendziwiat M, Hajjir N, Zhao M, Hsieh TC, Schubach M, Gurovich Y, Fleischer N, Jäger M, Köhler S, Muhle H, Korff C, Møller RS, Bayat A, Calvas P, Chassaing N, Warren H, Skinner S, Louie R, Evers C, Bohn M, Christen HJ, van den Born M, Obersztyn E, Charzewska A, Endziniene M, Kortüm F, Brown N, Robinson PN, Schelhaas HJ, Weber Y, Helbig I, Mundlos S, Horn D, Krawitz PM. Characterization of glycosylphosphatidylinositol biosynthesis defects by clinical features, flow cytometry, and automated image analysis. Genome Med 2018; 10:3. [PMID: 29310717 PMCID: PMC5759841 DOI: 10.1186/s13073-017-0510-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 12/11/2017] [Indexed: 12/17/2022] Open
Abstract
Background Glycosylphosphatidylinositol biosynthesis defects (GPIBDs) cause a group of phenotypically overlapping recessive syndromes with intellectual disability, for which pathogenic mutations have been described in 16 genes of the corresponding molecular pathway. An elevated serum activity of alkaline phosphatase (AP), a GPI-linked enzyme, has been used to assign GPIBDs to the phenotypic series of hyperphosphatasia with mental retardation syndrome (HPMRS) and to distinguish them from another subset of GPIBDs, termed multiple congenital anomalies hypotonia seizures syndrome (MCAHS). However, the increasing number of individuals with a GPIBD shows that hyperphosphatasia is a variable feature that is not ideal for a clinical classification. Methods We studied the discriminatory power of multiple GPI-linked substrates that were assessed by flow cytometry in blood cells and fibroblasts of 39 and 14 individuals with a GPIBD, respectively. On the phenotypic level, we evaluated the frequency of occurrence of clinical symptoms and analyzed the performance of computer-assisted image analysis of the facial gestalt in 91 individuals. Results We found that certain malformations such as Morbus Hirschsprung and diaphragmatic defects are more likely to be associated with particular gene defects (PIGV, PGAP3, PIGN). However, especially at the severe end of the clinical spectrum of HPMRS, there is a high phenotypic overlap with MCAHS. Elevation of AP has also been documented in some of the individuals with MCAHS, namely those with PIGA mutations. Although the impairment of GPI-linked substrates is supposed to play the key role in the pathophysiology of GPIBDs, we could not observe gene-specific profiles for flow cytometric markers or a correlation between their cell surface levels and the severity of the phenotype. In contrast, it was facial recognition software that achieved the highest accuracy in predicting the disease-causing gene in a GPIBD. Conclusions Due to the overlapping clinical spectrum of both HPMRS and MCAHS in the majority of affected individuals, the elevation of AP and the reduced surface levels of GPI-linked markers in both groups, a common classification as GPIBDs is recommended. The effectiveness of computer-assisted gestalt analysis for the correct gene inference in a GPIBD and probably beyond is remarkable and illustrates how the information contained in human faces is pivotal in the delineation of genetic entities. Electronic supplementary material The online version of this article (doi:10.1186/s13073-017-0510-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Alexej Knaus
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany
| | - Jean Tori Pantel
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Manuela Pendziwiat
- Department of Neuropediatrics, University Medical Center Schleswig Holstein, 24105, Kiel, Germany
| | - Nurulhuda Hajjir
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Max Zhao
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Tzung-Chien Hsieh
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany
| | - Max Schubach
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), 10178, Berlin, Germany
| | | | | | - Marten Jäger
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), 10178, Berlin, Germany
| | - Sebastian Köhler
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Hiltrud Muhle
- Department of Neuropediatrics, University Medical Center Schleswig Holstein, 24105, Kiel, Germany
| | - Christian Korff
- Unité de Neuropédiatrie, Université de Genève, CH-1211, Genève, Switzerland
| | - Rikke S Møller
- Danish Epilepsy Centre, DK-4293, Dianalund, Denmark.,Institute for Regional Health Services Research, University of Southern Denmark, DK-5000, Odense, Denmark
| | - Allan Bayat
- Department of Pediatrics, University Hospital of Hvidovre, 2650, Hvicovre, Denmark
| | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU, 31059, Toulouse, France
| | - Nicolas Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU, 31059, Toulouse, France
| | | | | | | | - Christina Evers
- Genetische Poliklinik, Universitätsklinik Heidelberg, 69120, Heidelberg, Germany
| | - Marc Bohn
- St. Bernward Krankenhaus, 31134, Hildesheim, Germany
| | - Hans-Jürgen Christen
- Kinderkrankenhaus auf der Bult, Hannoversche Kinderheilanstalt, 30173, Hannover, Germany
| | | | - Ewa Obersztyn
- Institute of Mother and Child Department of Molecular Genetics, 01-211, Warsaw, Poland
| | - Agnieszka Charzewska
- Institute of Mother and Child Department of Molecular Genetics, 01-211, Warsaw, Poland
| | - Milda Endziniene
- Neurology Department, Lithuanian University of Health Sciences, 50009, Kaunas, Lithuania
| | - Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Natasha Brown
- Victorian Clinical Genetics Services, Royal Children's Hospital, MCRI, Parkville, Australia.,Department of Clinical Genetics, Austin Health, Heidelberg, Australia
| | - Peter N Robinson
- The Jackson Laboratory for Genomic Medicine, 06032, Farmington, USA
| | - Helenius J Schelhaas
- Departement of Neurology, Academic Center for Epileptology, 5590, Heeze, The Netherlands
| | - Yvonne Weber
- Department of Neurology and Epileptology and Hertie Institute for Clinical Brain Research, University Tübingen, 72076, Tübingen, Germany
| | - Ingo Helbig
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany.,Pediatric Neurology, Children's Hospital of Philadelphia, 3401, Philadelphia, USA
| | - Stefan Mundlos
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Denise Horn
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.
| | - Peter M Krawitz
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany. .,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany. .,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany.
| |
Collapse
|
20
|
Reynolds KK, Juusola J, Rice GM, Giampietro PF. Prenatal presentation of Mabry syndrome with congenital diaphragmatic hernia and phenotypic overlap with Fryns syndrome. Am J Med Genet A 2017; 173:2776-2781. [PMID: 28817240 DOI: 10.1002/ajmg.a.38379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 06/28/2017] [Accepted: 07/01/2017] [Indexed: 12/19/2022]
Abstract
We report on a family in which initial features were compatible with Fryns syndrome. The first sibling was a stillborn female with a left diaphragmatic hernia (DH). Her clinical features overlapped with Fryns syndrome. The second pregnancy, a male fetus, was followed for polyhydramnios, hypoplastic mandible, mild enlargement of the fetal bladder, hydronephrosis, and rocker bottom foot deformities. He had facial features similar to his sibling and a large cleft of the secondary palate, small jaw, and secundum atrial septal defect. He underwent surgical repair of imperforate anus, intestinal malrotation, and placement of mucous fistula for biopsy positive Hirschsprung disease. An elevated alkaline phosphatase level of 1569 U/L was reported. Whole exome sequencing performed on the second child demonstrated compound heterozygosity for the PIGV gene with the p.A341E and p.A418D variants in trans. Hyperphosphatasia with mental retardation syndrome (HPMRS) is caused by mutations in PIGV and includes hyperphosphatasia as a diagnostic hallmark. Our patient exhibited hyperphosphatasia but without any storage material in his skin cells. His features remain similar to his sister's, but includes seizures and lacks diaphragmatic hernia. Until now, HPMRS and Fryns syndrome, despite overlapping features, were considered mutually exclusive as HPMRS involves hyperphosphatasia and Fryns typically exhibits DH. Recent identification of PIGN mutations associated with several cases of Fryns syndrome point to a common pathogenetic etiology involving inborn errors of the glycosylphosphatidylinositiol anchor biosynthetic pathway. A diagnosis of HPMRS should be considered when DH is encountered on prenatal ultrasound.
Collapse
|
21
|
Abdel-Hamid M, Issa M, Otaify G, Abdel-Ghafar S, Elbendary H, Zaki M. PGAP3
-related hyperphosphatasia with mental retardation syndrome: Report of 10 new patients and a homozygous founder mutation. Clin Genet 2017; 93:84-91. [DOI: 10.1111/cge.13033] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 11/27/2022]
Affiliation(s)
- M.S. Abdel-Hamid
- Medical Molecular Genetics Department, Human Genetics and Genome Research Division; National Research Centre; Cairo Egypt
| | - M.Y. Issa
- Clinical Genetics Department, Human Genetics and Genome Research Division; National Research Centre; Cairo Egypt
| | - G.A. Otaify
- Clinical Genetics Department, Human Genetics and Genome Research Division; National Research Centre; Cairo Egypt
| | - S.F. Abdel-Ghafar
- Medical Molecular Genetics Department, Human Genetics and Genome Research Division; National Research Centre; Cairo Egypt
| | - H.M. Elbendary
- Child Health Department, Medical Research Division; National Research Centre; Cairo Egypt
| | - M.S. Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division; National Research Centre; Cairo Egypt
| |
Collapse
|
22
|
Tanigawa J, Mimatsu H, Mizuno S, Okamoto N, Fukushi D, Tominaga K, Kidokoro H, Muramatsu Y, Nishi E, Nakamura S, Motooka D, Nomura N, Hayasaka K, Niihori T, Aoki Y, Nabatame S, Hayakawa M, Natsume J, Ozono K, Kinoshita T, Wakamatsu N, Murakami Y. Phenotype-genotype correlations of PIGO deficiency with variable phenotypes from infantile lethality to mild learning difficulties. Hum Mutat 2017; 38:805-815. [PMID: 28337824 DOI: 10.1002/humu.23219] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/15/2017] [Accepted: 03/19/2017] [Indexed: 01/23/2023]
Abstract
Inherited GPI (glycosylphosphatidylinositol) deficiencies (IGDs), a recently defined group of diseases, show a broad spectrum of symptoms. Hyperphosphatasia mental retardation syndrome, also known as Mabry syndrome, is a type of IGDs. There are at least 26 genes involved in the biosynthesis and transport of GPI-anchored proteins; however, IGDs constitute a rare group of diseases, and correlations between the spectrum of symptoms and affected genes or the type of mutations have not been shown. Here, we report four newly identified and five previously described Japanese families with PIGO (phosphatidylinositol glycan anchor biosynthesis class O) deficiency. We show how the clinical severity of IGDs correlates with flow cytometric analysis of blood, functional analysis using a PIGO-deficient cell line, and the degree of hyperphosphatasia. The flow cytometric analysis and hyperphosphatasia are useful for IGD diagnosis, but the expression level of GPI-anchored proteins and the degree of hyperphosphatasia do not correlate, although functional studies do, with clinical severity. Compared with PIGA (phosphatidylinositol glycan anchor biosynthesis class A) deficiency, PIGO deficiency shows characteristic features, such as Hirschsprung disease, brachytelephalangy, and hyperphosphatasia. This report shows the precise spectrum of symptoms according to the severity of mutations and compares symptoms between different types of IGD.
Collapse
Affiliation(s)
- Junpei Tanigawa
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Haruka Mimatsu
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Seiji Mizuno
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan
| | - Daisuke Fukushi
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Koji Tominaga
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.,Department of Child Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Hiroyuki Kidokoro
- Department of Pediatrics, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Yukako Muramatsu
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Eriko Nishi
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Shota Nakamura
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Daisuke Motooka
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Noriko Nomura
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Kiyoshi Hayasaka
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Yamagata, Japan
| | - Tetsuya Niihori
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Shin Nabatame
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Masahiro Hayakawa
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Jun Natsume
- Department of Developmental Disability Medicine and Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases Osaka University, Suita, Osaka, Japan
| | - Nobuaki Wakamatsu
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases Osaka University, Suita, Osaka, Japan
| |
Collapse
|
23
|
Johnstone DL, Nguyen TTM, Murakami Y, Kernohan KD, Tétreault M, Goldsmith C, Doja A, Wagner JD, Huang L, Hartley T, St-Denis A, le Deist F, Majewski J, Bulman DE, Kinoshita T, Dyment DA, Boycott KM, Campeau PM. Compound heterozygous mutations in the gene PIGP are associated with early infantile epileptic encephalopathy. Hum Mol Genet 2017; 26:1706-1715. [DOI: 10.1093/hmg/ddx077] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/27/2017] [Indexed: 12/27/2022] Open
Affiliation(s)
- Devon L. Johnstone
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Thi-Tuyet-Mai Nguyen
- Research Center, CHU Sainte-Justine, University of Montreal, Montreal, Quebec H3T1C5, Canada
| | - Yoshiko Murakami
- WPI Immunology Frontier Research Center and Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Kristin D. Kernohan
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Martine Tétreault
- Department of Human Genetics, McGill University, Montreal, Quebec H3A1B1, Canada
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec H3A0G1, Canada
| | - Claire Goldsmith
- Department of Genetics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario K1H8L1, Canada
| | - Asif Doja
- Division of Neurology, Department of Pediatrics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario K1H8L1, Canada
| | - Justin D. Wagner
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Lijia Huang
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Taila Hartley
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Anik St-Denis
- Research Center, CHU Sainte-Justine, University of Montreal, Montreal, Quebec H3T1C5, Canada
| | - Françoise le Deist
- Research Center, CHU Sainte-Justine, University of Montreal, Montreal, Quebec H3T1C5, Canada
| | - Jacek Majewski
- Department of Human Genetics, McGill University, Montreal, Quebec H3A1B1, Canada
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec H3A0G1, Canada
| | - Dennis E. Bulman
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
| | - Taroh Kinoshita
- WPI Immunology Frontier Research Center and Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - David A. Dyment
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
- Department of Genetics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario K1H8L1, Canada
| | - Kym M. Boycott
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada
- Department of Genetics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario K1H8L1, Canada
| | - Philippe M. Campeau
- Research Center, CHU Sainte-Justine, University of Montreal, Montreal, Quebec H3T1C5, Canada
- Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, Montreal, Quebec H3T1C5, Canada
| | | |
Collapse
|
24
|
Xue J, Li H, Zhang Y, Yang Z. Clinical and genetic analysis of two Chinese infants with Mabry syndrome. Brain Dev 2016; 38:807-18. [PMID: 27177984 DOI: 10.1016/j.braindev.2016.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/05/2016] [Accepted: 04/12/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Hyperphosphatasia mental retardation syndrome (Mabry syndrome) is an autosomal recessive disorder. We aim to analyze two Chinese patients diagnosed as Mabry syndrome. METHODS The clinical manifestations, diagnosis and treatment were observed in two patients. Genetic analysis including PIGV and PIGO was examined. RESULTS Two patients were diagnosed as Mabry syndrome clinically and genetically. Developmental delay, hyperphosphatasia and seizures were presented in both of them. Typical facial dysmorphism and hypoplastic terminal phalanges were only found in one. Some novel presentations including congenital laryngeal cartilage softening, inguinal hernia, broken palmprint, optic atrophy and skeleton dysplasia such as carpal age delay and metaphysis anomalies were observed in two patients. Molecular genetic analysis revealed compound heterozygous mutations of PIGV or PIGO in our patients, including c.615C>G (p.Asn205Lys) and c.854A>G (p.Tyr285Cys) of PIGV in patient 1, and c.458T>C (p.Phe153Ser) and c.1355_1356del (p.Ala452Glyfs*52) of PIGO in patient 2. Additionally, a heterozygous c.2926G>A (Asp976Asn) of PCDH19 was identified in patient with PIGV mutations, the causative gene of Epilepsy and mental retardation limited to females (EFMR). CONCLUSION To our best knowledge, this is the first time to report Chinese patients diagnosed as Mabry syndrome. For the PCDH19 mutation in our patient carrying PIGV mutations, due to lacking characteristics of EFMR and the ambiguity results in pathogenicity analysis, we were not sure how much pathogenic role PCDH19 mutation shared with PIGV mutations in this disease. The novel mutations of PIGV and PIGO, and novel clinical manifestations reported here might expand the genotype and phenotype spectrum of Mabry syndrome.
Collapse
Affiliation(s)
- Jiao Xue
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Hui Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.
| |
Collapse
|
25
|
Abstract
Hypophosphatasia (HPP) is due to deficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNAP). This enzyme cleaves extracellular substrates inorganic pyrophosphates (PPi), pyridoxal-5'-phosphate (PLP), phosphoethanolamine (PEA) and nucleotides, and probably other substrates not yet identified. During the last 15 years the role of TNAP in mineralization, and to a less degree in brain, has been investigated, providing hypotheses and explanations for both bone and neuronal HPP phenotypes. ALPL, the gene encoding TNAP, is subject to many mutations, mostly missense mutations. A few number of mutations are recurrently found and may be quite frequent in particular populations. This reflects founder effects. The great variety of mutations results in a great number of compound heterozygous genotypes and in highly variable clinical expressivity. A good correlation was observed between the severity of the disease and in vitro enzymatic activity of the mutant protein measured after site-directed mutagenesis. Many missense mutations found in severe hypophosphatasia produced a mutant protein that failed to reach the cell membrane , was accumulated in the cis-Golgi and was subsequently degraded in the proteasome. Missense mutations located in the catalytic site or in the homodimer interface were often shown by site-directed mutagenesis to have a dominant negative effect. Currently molecular diagnosis of HPP is based on the sequencing of the coding sequence of ALPL that allows detection of approximately 95 % of mutations in severe cases. In addition, other genes, especially genes encoding proteins involved in the regulation of extracellular PPi concentration, could modify the phenotype (modifier genes).
Collapse
|
26
|
Carmean V, Yonkers MA, Tellez MB, Willer JR, Willer GB, Gregg RG, Geisler R, Neuhauss SC, Ribera AB. pigk Mutation underlies macho behavior and affects Rohon-Beard cell excitability. J Neurophysiol 2015; 114:1146-57. [PMID: 26133798 DOI: 10.1152/jn.00355.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/25/2015] [Indexed: 12/20/2022] Open
Abstract
The study of touch-evoked behavior allows investigation of both the cells and circuits that generate a response to tactile stimulation. We investigate a touch-insensitive zebrafish mutant, macho (maco), previously shown to have reduced sodium current amplitude and lack of action potential firing in sensory neurons. In the genomes of mutant but not wild-type embryos, we identify a mutation in the pigk gene. The encoded protein, PigK, functions in attachment of glycophosphatidylinositol anchors to precursor proteins. In wild-type embryos, pigk mRNA is present at times when mutant embryos display behavioral phenotypes. Consistent with the predicted loss of function induced by the mutation, knock-down of PigK phenocopies maco touch insensitivity and leads to reduced sodium current (INa) amplitudes in sensory neurons. We further test whether the genetic defect in pigk underlies the maco phenotype by overexpressing wild-type pigk in mutant embryos. We find that ubiquitous expression of wild-type pigk rescues the touch response in maco mutants. In addition, for maco mutants, expression of wild-type pigk restricted to sensory neurons rescues sodium current amplitudes and action potential firing in sensory neurons. However, expression of wild-type pigk limited to sensory cells of mutant embryos does not allow rescue of the behavioral touch response. Our results demonstrate an essential role for pigk in generation of the touch response beyond that required for maintenance of proper INa density and action potential firing in sensory neurons.
Collapse
Affiliation(s)
- V Carmean
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - M A Yonkers
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - M B Tellez
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - J R Willer
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - G B Willer
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - R G Gregg
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - R Geisler
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
| | - S C Neuhauss
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
| | - A B Ribera
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado;
| |
Collapse
|
27
|
Abstract
An autosomal recessive syndrome of hyperphosphatasia (elevated circulating alkaline phosphatase (AP), seizures and neurologic deficits) was first described by Mabry and colleagues in 1970. Over the ensuing four decades, few cases were reported. In 2010, however, new families were identified and the syndromic nature of the disorder confirmed. Shortly thereafter, next generation sequencing was used to characterize causative defects in the glycosyl phosphatidylinositol (GPI) biosynthetic pathway, based partly on our understanding of how AP is anchored by GPI to the plasma membrane. Whether the seizures and cognitive defects seen in Mabry syndrome patients are attributable in part to the constant hyperphosphatasia is not known, as there are more than 250 other proteins dependent on GPI for their anchoring to the plasma membrane. However, Mabry syndrome may provide a new window on AP function in growth and development.
Collapse
Affiliation(s)
- David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada,
| | | |
Collapse
|
28
|
Abstract
Two observations stimulated the interest in vitamin B-6 and alkaline phosphatase in brain: the marked increase in plasma pyridoxal phosphate and the occurrence of pyridoxine responsive seizures in hypophosphatasia. The increase in plasma pyridoxal phosphate indicates the importance of tissue non-specific alkaline phosphatase (TNAP) in transferring vitamin B-6 into the tissues. Vitamin B-6 is involved in the biosynthesis of most of the neurotransmitters. Decreased gamma-aminobutyrate (GABA) appears to be most directly related to the development of seizures in vitamin B-6 deficiency. Cytosolic pyridoxal phosphatase/chronophin may interact with vitamin B-6 metabolism and neuronal development and function. Ethanolaminephosphate phospholyase interacts with phosphoethanolamine metabolism. Extracellular pyridoxal phosphate may interact with purinoceptors and calcium channels. In conclusion, TNAP clearly influences extracellular and intracellular metabolism of vitamin B-6 in brain, particularly during developmental stages. While effects on GABA metabolism appear to be the major contributor to seizures, multiple other intra- and extra-cellular metabolic systems may be affected directly and/or indirectly by altered vitamin B-6 hydrolysis and uptake resulting from variations in alkaline phosphatase activity.
Collapse
|
29
|
Martin HC, Kim GE, Pagnamenta AT, Murakami Y, Carvill GL, Meyer E, Copley RR, Rimmer A, Barcia G, Fleming MR, Kronengold J, Brown MR, Hudspith KA, Broxholme J, Kanapin A, Cazier JB, Kinoshita T, Nabbout R, Bentley D, McVean G, Heavin S, Zaiwalla Z, McShane T, Mefford HC, Shears D, Stewart H, Kurian MA, Scheffer IE, Blair E, Donnelly P, Kaczmarek LK, Taylor JC. Clinical whole-genome sequencing in severe early-onset epilepsy reveals new genes and improves molecular diagnosis. Hum Mol Genet 2014; 23:3200-11. [PMID: 24463883 PMCID: PMC4030775 DOI: 10.1093/hmg/ddu030] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/20/2014] [Indexed: 11/13/2022] Open
Abstract
In severe early-onset epilepsy, precise clinical and molecular genetic diagnosis is complex, as many metabolic and electro-physiological processes have been implicated in disease causation. The clinical phenotypes share many features such as complex seizure types and developmental delay. Molecular diagnosis has historically been confined to sequential testing of candidate genes known to be associated with specific sub-phenotypes, but the diagnostic yield of this approach can be low. We conducted whole-genome sequencing (WGS) on six patients with severe early-onset epilepsy who had previously been refractory to molecular diagnosis, and their parents. Four of these patients had a clinical diagnosis of Ohtahara Syndrome (OS) and two patients had severe non-syndromic early-onset epilepsy (NSEOE). In two OS cases, we found de novo non-synonymous mutations in the genes KCNQ2 and SCN2A. In a third OS case, WGS revealed paternal isodisomy for chromosome 9, leading to identification of the causal homozygous missense variant in KCNT1, which produced a substantial increase in potassium channel current. The fourth OS patient had a recessive mutation in PIGQ that led to exon skipping and defective glycophosphatidyl inositol biosynthesis. The two patients with NSEOE had likely pathogenic de novo mutations in CBL and CSNK1G1, respectively. Mutations in these genes were not found among 500 additional individuals with epilepsy. This work reveals two novel genes for OS, KCNT1 and PIGQ. It also uncovers unexpected genetic mechanisms and emphasizes the power of WGS as a clinical tool for making molecular diagnoses, particularly for highly heterogeneous disorders.
Collapse
Affiliation(s)
- Hilary C Martin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Grace E Kim
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Alistair T Pagnamenta
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Gemma L Carvill
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Esther Meyer
- Neurosciences Unit, UCL-Institute of Child Health, London, UK, Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Richard R Copley
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Andrew Rimmer
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Giulia Barcia
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | - Matthew R Fleming
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jack Kronengold
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Maile R Brown
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Karl A Hudspith
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - John Broxholme
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alexander Kanapin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Rima Nabbout
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Gil McVean
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Sinéad Heavin
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Zenobia Zaiwalla
- Department of Clinical Neurophysiology, John Radcliffe Hospital, Oxford, UK
| | - Tony McShane
- Department of Paediatrics, Children's Hospital Oxford, John Radcliffe Hospital, Oxford, UK
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Deborah Shears
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Helen Stewart
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Manju A Kurian
- Neurosciences Unit, UCL-Institute of Child Health, London, UK
| | - Ingrid E Scheffer
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Edward Blair
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Peter Donnelly
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Leonard K Kaczmarek
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jenny C Taylor
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK,
| |
Collapse
|
30
|
Howard M, Murakami Y, Pagnamenta A, Daumer-Haas C, Fischer B, Hecht J, Keays D, Knight S, Kölsch U, Krüger U, Leiz S, Maeda Y, Mitchell D, Mundlos S, Phillips J, Robinson P, Kini U, Taylor J, Horn D, Kinoshita T, Krawitz P. Mutations in PGAP3 impair GPI-anchor maturation, causing a subtype of hyperphosphatasia with mental retardation. Am J Hum Genet 2014; 94:278-87. [PMID: 24439110 DOI: 10.1016/j.ajhg.2013.12.012] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/11/2013] [Indexed: 12/11/2022] Open
Abstract
Glycosylphophatidylinositol (GPI)-anchored proteins play important roles in many biological processes, and mutations affecting proteins involved in the synthesis of the GPI anchor are reported to cause a wide spectrum of intellectual disabilities (IDs) with characteristic additional phenotypic features. Here, we describe a total of five individuals (from three unrelated families) in whom we identified mutations in PGAP3, encoding a protein that is involved in GPI-anchor maturation. Three siblings in a consanguineous Pakistani family presented with profound developmental delay, severe ID, no speech, psychomotor delay, and postnatal microcephaly. A combination of autozygosity mapping and exome sequencing identified a 13.8 Mb region harboring a homozygous c.275G>A (p.Gly92Asp) variant in PGAP3 region 17q11.2-q21.32. Subsequent testing showed elevated serum alkaline phosphatase (ALP), a GPI-anchored enzyme, in all three affected children. In two unrelated individuals in a cohort with developmental delay, ID, and elevated ALP, we identified compound-heterozygous variants c.439dupC (p.Leu147Profs(∗)16) and c.914A>G (p.Asp305Gly) and homozygous variant c.314C>G (p.Pro105Arg). The 1 bp duplication causes a frameshift and nonsense-mediated decay. Further evidence supporting pathogenicity of the missense mutations c.275G>A, c.314C>G, and c.914A>G was provided by the absence of the variants from ethnically matched controls, phylogenetic conservation, and functional studies on Chinese hamster ovary cell lines. Taken together with recent data on PGAP2, these results confirm the importance of the later GPI-anchor remodelling steps for normal neuronal development. Impairment of PGAP3 causes a subtype of hyperphosphatasia with ID, a congenital disorder of glycosylation that is also referred to as Mabry syndrome.
Collapse
|
31
|
Horn D, Wieczorek D, Metcalfe K, Barić I, Paležac L, Cuk M, Petković Ramadža D, Krüger U, Demuth S, Heinritz W, Linden T, Koenig J, Robinson PN, Krawitz P. Delineation of PIGV mutation spectrum and associated phenotypes in hyperphosphatasia with mental retardation syndrome. Eur J Hum Genet 2013; 22:762-7. [PMID: 24129430 DOI: 10.1038/ejhg.2013.241] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 09/13/2013] [Accepted: 09/18/2013] [Indexed: 11/09/2022] Open
Abstract
Three different genes of the glycosylphosphatidylinositol anchor synthesis pathway, PIGV, PIGO, and PGAP2, have recently been implicated in hyperphosphatasia-mental retardation syndrome (HPMRS), also known as Mabry syndrome, a rare autosomal recessive form of intellectual disability. The aim of this study was to delineate the PIGV mutation spectrum as well as the associated phenotypic spectrum in a cohort of 16 individuals diagnosed with HPMRS on the basis of intellectual disability and elevated serum alkaline phosphate as minimal diagnostic criteria. All PIGV exons and intronic boundaries were sequenced in 16 individuals. Biallelic PIGV mutations were identified in 8 of 16 unrelated families with HPMRS. The most frequent mutation detected in about 80% of affected families including the cases reported here is the c.1022C>A PIGV mutation, which was found in both the homozygous as well as the heterozygous state. Four further mutations found in this study (c. 176T>G, c.53G>A, c.905T>C, and c.1405C>T) are novel. Our findings in the largest reported cohort to date significantly extend the range of reported manifestations associated with PIGV mutations and demonstrate that the severe end of the clinical spectrum presents as a multiple congenital malformation syndrome with a high frequency of Hirschsprung disease, vesicoureteral, and renal anomalies as well as anorectal malformations. PIGV mutations are the major cause of HPMRS, which displays a broad clinical variability regarding associated malformations and growth patterns. Severe developmental delays, particular facial anomalies, brachytelephalangy, and hyperphosphatasia are consistently found in PIGV-positive individuals.
Collapse
Affiliation(s)
- Denise Horn
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik Essen, Universitätsklinikum Essen, Essen, Germany
| | - Kay Metcalfe
- Clinical Genetics, Genetic Medicine, St Mary's Hospital, Manchester, UK
| | - Ivo Barić
- 1] Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia [2] University of Zagreb, School of Medicine, Zagreb, Croatia
| | - Lidija Paležac
- University of Zagreb, School of Medicine, Zagreb, Croatia
| | - Mario Cuk
- 1] Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia [2] University of Zagreb, School of Medicine, Zagreb, Croatia
| | | | - Ulrike Krüger
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | | | - Tobias Linden
- Klinik für Kinder- und Jugendmedizin, Universitätsklinikum Münster, Münster, Germany
| | - Jens Koenig
- Klinik für Kinder- und Jugendmedizin, Universitätsklinikum Münster, Münster, Germany
| | - Peter N Robinson
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Krawitz
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
32
|
Thompson MD, Sharom FJ, Phillips JA, Robinson PN, Cole DE, Andrade DM. 9. Phenotypic variability in Mabry syndrome: Hyperphosphatasia with seizures and neurologic deficit. Clin Neurophysiol 2013. [DOI: 10.1016/j.clinph.2012.08.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
33
|
Kvarnung M, Nilsson D, Lindstrand A, Korenke GC, Chiang SCC, Blennow E, Bergmann M, Stödberg T, Mäkitie O, Anderlid BM, Bryceson YT, Nordenskjöld M, Nordgren A. A novel intellectual disability syndrome caused by GPI anchor deficiency due to homozygous mutations inPIGT. J Med Genet 2013; 50:521-8. [DOI: 10.1136/jmedgenet-2013-101654] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
34
|
Krawitz P, Murakami Y, Rieß A, Hietala M, Krüger U, Zhu N, Kinoshita T, Mundlos S, Hecht J, Robinson P, Horn D. PGAP2 mutations, affecting the GPI-anchor-synthesis pathway, cause hyperphosphatasia with mental retardation syndrome. Am J Hum Genet 2013; 92:584-9. [PMID: 23561847 DOI: 10.1016/j.ajhg.2013.03.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 01/28/2013] [Accepted: 03/15/2013] [Indexed: 01/02/2023] Open
Abstract
Recently, mutations in genes involved in the biosynthesis of the glycosylphosphatidylinositol (GPI) anchor have been identified in a new subclass of congenital disorders of glycosylation (CDGs) with a distinct spectrum of clinical features. To date, mutations have been identified in six genes (PIGA, PIGL, PIGM, PIGN, PIGO, and PIGV) encoding proteins in the GPI-anchor-synthesis pathway in individuals with severe neurological features, including seizures, muscular hypotonia, and intellectual disability. We developed a diagnostic gene panel for targeting all known genes encoding proteins in the GPI-anchor-synthesis pathway to screen individuals matching these features, and we detected three missense mutations in PGAP2, c.46C>T, c.380T>C, and c.479C>T, in two unrelated individuals with hyperphosphatasia with mental retardation syndrome (HPMRS). The mutations cosegregated in the investigated families. PGAP2 is involved in fatty-acid GPI-anchor remodeling, which occurs in the Golgi apparatus and is required for stable association between GPI-anchored proteins and the cell-surface membrane rafts. Transfection of the altered protein constructs, p.Arg16Trp (NP_001243169.1), p.Leu127Ser, and p.Thr160Ile, into PGAP2-null cells showed only partial restoration of GPI-anchored marker proteins, CD55 and CD59, on the cell surface. In this work, we show that an impairment of GPI-anchor remodeling also causes HPMRS and conclude that targeted sequencing of the genes encoding proteins in the GPI-anchor-synthesis pathway is an effective diagnostic approach for this subclass of CDGs.
Collapse
|
35
|
Coutton C, Bidart M, Rendu J, Devillard F, Vieville G, Amblard F, Lopez G, Jouk PS, Satre V. 190-kb duplication in 1p36.11 includingPIGVandARID1Agenes in a girl with intellectual disability and hexadactyly. Clin Genet 2013; 84:596-9. [DOI: 10.1111/cge.12113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/23/2013] [Accepted: 01/23/2013] [Indexed: 11/29/2022]
Affiliation(s)
- C Coutton
- Laboratoire de Génétique Chromosomique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
- Equipe “Génétique, Infertilité et Thérapeutique”; Laboratoire AGIM, CNRS FRE3405; Grenoble France
- Université Joseph Fourier; Grenoble France
| | - M Bidart
- Université Joseph Fourier; Grenoble France
- INSERM, U836, Team7 Nanomedicine and Brain, BP 170; Grenoble France
- Biology and Pathology Institute; University Hospital Centre; Grenoble France
| | - J Rendu
- Université Joseph Fourier; Grenoble France
- Laboratoire de Biochimie et Génétique Moléculaire; CHU Grenoble; Grenoble France
| | - F Devillard
- Laboratoire de Génétique Chromosomique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
| | - G Vieville
- Laboratoire de Génétique Chromosomique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
| | - F Amblard
- Laboratoire de Génétique Chromosomique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
| | - G Lopez
- Service de Génétique Clinique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
| | - P-S Jouk
- Université Joseph Fourier; Grenoble France
- Service de Génétique Clinique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
| | - V Satre
- Laboratoire de Génétique Chromosomique, Département de Génétique et Procréation; Hôpital Couple Enfant, CHU Grenoble; Grenoble France
- Equipe “Génétique, Infertilité et Thérapeutique”; Laboratoire AGIM, CNRS FRE3405; Grenoble France
- Université Joseph Fourier; Grenoble France
| |
Collapse
|
36
|
Mutations in PIGO, a member of the GPI-anchor-synthesis pathway, cause hyperphosphatasia with mental retardation. Am J Hum Genet 2012; 91:146-51. [PMID: 22683086 DOI: 10.1016/j.ajhg.2012.05.004] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 04/19/2012] [Accepted: 05/11/2012] [Indexed: 11/23/2022] Open
Abstract
Hyperphosphatasia with mental retardation syndrome (HPMRS), an autosomal-recessive form of intellectual disability characterized by facial dysmorphism, seizures, brachytelephalangy, and persistent elevated serum alkaline phosphatase (hyperphosphatasia), was recently shown to be caused by mutations in PIGV, a member of the glycosylphosphatidylinositol (GPI)-anchor-synthesis pathway. However, not all individuals with HPMRS harbor mutations in this gene. By exome sequencing, we detected compound-heterozygous mutations in PIGO, a gene coding for a membrane protein of the same molecular pathway, in two siblings with HPMRS, and we then found by Sanger sequencing further mutations in another affected individual; these mutations cosegregated in the investigated families. The mutant transcripts are aberrantly spliced, decrease the membrane stability of the protein, or impair enzyme function such that GPI-anchor synthesis is affected and the level of GPI-anchored substrates localized at the cell surface is reduced. Our data identify PIGO as the second gene associated with HPMRS and suggest that a deficiency in GPI-anchor synthesis is the underlying molecular pathomechanism of HPMRS.
Collapse
|