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Sadamitsu K, Yanagi K, Hasegawa Y, Murakami Y, Low SE, Ooshima D, Matsubara Y, Okamoto N, Kaname T, Hirata H. A novel homozygous variant of the PIGK gene caused by paternal disomy in a patient with neurodevelopmental disorder, cerebellar atrophy, and seizures. J Hum Genet 2024:10.1038/s10038-024-01264-3. [PMID: 38902431 DOI: 10.1038/s10038-024-01264-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/27/2024] [Accepted: 05/30/2024] [Indexed: 06/22/2024]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins are located at the cell surface by a covalent attachment between protein and GPI embedded in the plasma membrane. This attachment is catalyzed by GPI transamidase comprising five subunits (PIGK, PIGS, PIGT, PIGU, and GPAA1) in the endoplasmic reticulum. Loss of either subunit of GPI transamidase eliminates cell surface localization of GPI-anchored proteins. In humans, pathogenic variants in either subunit of GPI transamidase cause neurodevelopmental disorders. However, how the loss of GPI-anchored proteins triggers neurodevelopmental defects remains largely unclear. Here, we identified a novel homozygous variant of PIGK, NM_005482:c.481A > G,p. (Met161Val), in a Japanese female patient with neurodevelopmental delay, hypotonia, cerebellar atrophy, febrile seizures, hearing loss, growth impairment, dysmorphic facial features, and brachydactyly. The missense variant was found heterozygous in her father, but not in her mother. Zygosity analysis revealed that the homozygous PIGK variant in the patient was caused by paternal isodisomy. Rescue experiments using PIGK-deficient CHO cells revealed that the p.Met161Val variant of PIGK reduced GPI transamidase activity. Rescue experiments using pigk mutant zebrafish confirmed that the p.Met161Val variant compromised PIGK function in tactile-evoked motor response. We also demonstrated that axonal localization of voltage-gated sodium channels and concomitant generation of action potentials were impaired in pigk-deficient neurons in zebrafish, suggesting a link between GPI-anchored proteins and neuronal defects. Taken together, the missense p.Met161Val variant of PIGK is a novel pathogenic variant that causes the neurodevelopmental disorder.
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Affiliation(s)
- Kenichiro Sadamitsu
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Kumiko Yanagi
- Department of Genome Medicine, National Center for Child Health and Development, Tokyo, 157-8535, Japan
| | - Yuiko Hasegawa
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, 594-1101, Japan
| | - Yoshiko Murakami
- Laboratory of Immunoglycobiology, Research Institute for Microbial Diseases, Osaka University, Suita, 565-0871, Japan
| | - Sean E Low
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Daikun Ooshima
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Yoichi Matsubara
- National Center for Child Health and Development, Tokyo, 157-8535, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, 594-1101, Japan
| | - Tadashi Kaname
- Department of Genome Medicine, National Center for Child Health and Development, Tokyo, 157-8535, Japan.
| | - Hiromi Hirata
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan.
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Ranjan A, Alam MS, Kumar V, Kumar R, Saifullah KM, Fakih S. Spectrum of Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome 3 (MCAHS3) Due to Phosphatidylinositol Glycan Biosynthesis Class T (PIGT) Gene Mutations: A Narrative Review. Cureus 2024; 16:e60737. [PMID: 38903302 PMCID: PMC11187727 DOI: 10.7759/cureus.60737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2024] [Indexed: 06/22/2024] Open
Abstract
Multiple congenital anomalies-hypotonia-seizures syndrome 3 (MCAHS3) results from mutations in the phosphatidylinositol glycan biosynthesis class T (PIGT) gene leading to defects in glycosylphosphatidylinositol transamidase complex (GPI-TA) synthesis. Glycosylphosphatidylinositol serves as an anchor to more than 150 mammalian proteins for attachment on cell surfaces, enabling specific functional properties. Mutations in the PIGT gene result in disruption of this extremely important post-translational protein modification, yielding dysfunctional proteins leading to MCAHS3. An exhaustive literature search was conducted across various electronic databases to reveal only 41 reported cases of MCAHS3 worldwide, emphasizing the rarity of this condition. Multiple congenital anomalies-hypotonia-seizures syndrome 3 has been reported as secondary to 18 different known PIGT variants to date, manifesting as a varying spectrum of craniofacial dysmorphism, developmental delay with epilepsy, cardiac and renal malformations, and unique features in biochemical testing and neuroimaging. This review aims to highlight the constellation of clinical symptoms, diagnostic modalities, and management challenges associated with MCAHS3 cases. It would help determine optimal diagnostic and treatment strategies for newly identified cases and facilitate new research on this rare condition.
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Affiliation(s)
- Ankit Ranjan
- Department of Neonatology, Rani Hospital, Ranchi, IND
| | | | - Vinod Kumar
- Department of Neonatology, Rani Hospital, Ranchi, IND
| | - Rajesh Kumar
- Department of Neonatology, Rani Hospital, Ranchi, IND
| | | | - Sofia Fakih
- Department of Neonatology, Rani Hospital, Ranchi, IND
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3
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Gefen AM, Zaritsky JJ. Review of childhood genetic nephrolithiasis and nephrocalcinosis. Front Genet 2024; 15:1381174. [PMID: 38606357 PMCID: PMC11007102 DOI: 10.3389/fgene.2024.1381174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 03/04/2024] [Indexed: 04/13/2024] Open
Abstract
Nephrolithiasis (NL) is a common condition worldwide. The incidence of NL and nephrocalcinosis (NC) has been increasing, along with their associated morbidity and economic burden. The etiology of NL and NC is multifactorial and includes both environmental components and genetic components, with multiple studies showing high heritability. Causative gene variants have been detected in up to 32% of children with NL and NC. Children with NL and NC are genotypically heterogenous, but often phenotypically relatively homogenous, and there are subsequently little data on the predictors of genetic childhood NL and NC. Most genetic diseases associated with NL and NC are secondary to hypercalciuria, including those secondary to hypercalcemia, renal phosphate wasting, renal magnesium wasting, distal renal tubular acidosis (RTA), proximal tubulopathies, mixed or variable tubulopathies, Bartter syndrome, hyperaldosteronism and pseudohyperaldosteronism, and hyperparathyroidism and hypoparathyroidism. The remaining minority of genetic diseases associated with NL and NC are secondary to hyperoxaluria, cystinuria, hyperuricosuria, xanthinuria, other metabolic disorders, and multifactorial etiologies. Genome-wide association studies (GWAS) in adults have identified multiple polygenic traits associated with NL and NC, often involving genes that are involved in calcium, phosphorus, magnesium, and vitamin D homeostasis. Compared to adults, there is a relative paucity of studies in children with NL and NC. This review aims to focus on the genetic component of NL and NC in children.
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Affiliation(s)
- Ashley M. Gefen
- Phoenix Children’s Hospital, Department of Pediatrics, Division of Nephrology, Phoenix, AZ, United States
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Tan M, Pan Q, Yu C, Zhai X, Gu J, Tao L, Xu D. PIGT promotes cell growth, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking. J Transl Med 2024; 22:5. [PMID: 38169393 PMCID: PMC10763284 DOI: 10.1186/s12967-023-04805-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Bladder cancer is very common worldwide. PIGT is a subunit of the glycosylphosphatidylinositol transamidase which involves in tumorigenesis and invasiveness. m6A modification of mRNA has been linked to cell proliferation, tumor progression and other biological events. However, how PIGT is regulated and what is the function of PIGT in bladder cancer remains to be elucidated. METHODS PIGT was silenced or overexpressed to study its role in regulating bladder cancer. Cell proliferation and invasion were examined with the Cell Counting Kit-8, colony formation and Transwell assay, respectively. Cellular oxygen consumption rates or extracellular acidification rates were detected by a XF24 Analyzer. Quantitative RT-PCR and immunoblots were performed to detect mRNA and protein levels. RESULTS PIGT was overexpressed in bladder cancer. Silencing PIGT inhibited cell proliferation, oxidative phosphorylation, and glycolysis. Overexpressing PIGT promoted cell proliferation, oxidative phosphorylation, glycolysis in vitro and tumor metastasis in vivo by activating glucose transporter 1 (GLUT1). PIGT also promoted GLUT1 glycosylation and membrane trafficking. Wilms' tumor 1-associated protein (WTAP) mediated PIGT m6A modification, and m6A reader, insulin-like growth factor 2 mRNA-binding protein (IGF2BP2), binds to the methylated PIGT to promote the stability of PIGT, leading to up-regulation of PIGT. CONCLUSION WTAP mediates PIGT m6A modification to increase the stability of PIGT via the IGF2BP2, which enhances cell proliferation, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking.
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Affiliation(s)
- Mingyue Tan
- Urology Center, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Pudong New Area, Shanghai, 201203, China
| | - Qi Pan
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China
| | - Chao Yu
- Department of Urology and Andrology, Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Xinyu Zhai
- Urology Center, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Pudong New Area, Shanghai, 201203, China
| | - Jianyi Gu
- Urology Center, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Pudong New Area, Shanghai, 201203, China
| | - Le Tao
- Department of Urology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, No.160 Pujian Road, Pudong New Area, Shanghai, 200127, China.
| | - Dongliang Xu
- Urology Center, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, No. 528, Zhangheng Road, Pudong New Area, Shanghai, 201203, China.
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Ben Ayed I, Jallouli O, Murakami Y, Souissi A, Mallouli S, Bouzid A, Kamoun F, Elloumi I, Frikha F, Tlili A, Weckhuysen S, Kinoshita T, Triki CC, Masmoudi S. Case report: Functional analysis of the p.Arg507Trp variant of the PIGT gene supporting the moderate epilepsy phenotype of mutations in the C-terminal region. Front Neurol 2023; 14:1092887. [PMID: 36970549 PMCID: PMC10034188 DOI: 10.3389/fneur.2023.1092887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/01/2023] [Indexed: 03/29/2023] Open
Abstract
Pathogenic germline variants in the PIGT gene are associated with the "multiple congenital anomalies-hypotonia-seizures syndrome 3" (MCAHS3) phenotype. So far, fifty patients have been reported, most of whom suffer from intractable epilepsy. Recently, a comprehensive analysis of a cohort of 26 patients with PIGT variants has broadened the phenotypical spectrum and indicated that both p.Asn527Ser and p.Val528Met are associated with a milder epilepsy phenotype and less severe outcomes. Since all reported patients are of Caucasian/Polish origin and most harbor the same variant (p.Val528Met), the ability to draw definitive conclusions regarding the genotype-phenotype correlation remains limited. We report a new case with a homozygous variant p.Arg507Trp in the PIGT gene, detected on clinical exome sequencing. The North African patient in question displays a predominantly neurological phenotype with global developmental delay, hypotonia, brain abnormalities, and well-controlled epileptic seizures. Homozygous and heterozygous variants in codon 507 have been reported to cause PIGT deficiency without biochemical confirmation. In this study, FACS analysis of knockout HEK293 cells that had been transfected with wild-type or mutant cDNA constructs demonstrated that the p.Arg507Trp variant leads to mildly reduced activity. Our result confirm the pathogenicity of this variant and strengthen recently reported evidence on the genotype-phenotype correlation of the PIGT variant.
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Affiliation(s)
- Ikhlas Ben Ayed
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
- Medical Genetics Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
| | - Olfa Jallouli
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
- Research Laboratory “Neuropédiatrie” LR19ES15, Sfax University, Sfax, Tunisia
| | - Yoshiko Murakami
- Laboratory of Immunoglycobiology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Salma Mallouli
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
- Research Laboratory “Neuropédiatrie” LR19ES15, Sfax University, Sfax, Tunisia
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Fatma Kamoun
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
- Research Laboratory “Neuropédiatrie” LR19ES15, Sfax University, Sfax, Tunisia
| | - Ines Elloumi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Fakher Frikha
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
- Human Genetics and Stem Cell Laboratory, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates
| | | | - Taroh Kinoshita
- Laboratory of Immunoglycobiology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
- Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
| | - Chahnez Charfi Triki
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
- Research Laboratory “Neuropédiatrie” LR19ES15, Sfax University, Sfax, Tunisia
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
- *Correspondence: Saber Masmoudi
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Silksmith B, Munot P, Starling L, Pujar S, Matthews E. Accelerating the genetic diagnosis of neurological disorders presenting with episodic apnoea in infancy. THE LANCET. CHILD & ADOLESCENT HEALTH 2022; 6:495-508. [PMID: 35525254 DOI: 10.1016/s2352-4642(22)00091-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/25/2022] [Accepted: 03/03/2022] [Indexed: 11/26/2022]
Abstract
Unexplained episodic apnoea in infants (aged ≤1 year), including recurrent brief (<1 min) resolved unexplained events (known as BRUE), can be a diagnostic challenge. Recurrent unexplained apnoea might suggest a persistent, debilitating, and potentially fatal disorder. Genetic diseases are prevalent among this group, particularly in those who present with paroxysmal or episodic neurological symptoms. These disorders are individually rare and challenging for a general paediatrician to recognise, and there is often a delayed or even posthumous diagnosis (sometimes only made in retrospect when a second sibling becomes unwell). The disorders can be debilitating if untreated but pharmacotherapies are available for the vast majority. That any child should suffer from unnecessary morbidity or die from one of these disorders without a diagnosis or treatment having been offered is a tragedy; therefore, there is an urgent need to simplify and expedite the diagnostic journey. We propose an apnoea gene panel for hospital specialists caring for any infant who has recurrent apnoea without an obvious cause. This approach could remove the need to identify individual rare conditions, speed up diagnosis, and improve access to therapy, with the ultimate aim of reducing morbidity and mortality.
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Affiliation(s)
- Bryony Silksmith
- Department of Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Pinki Munot
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Luke Starling
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Suresh Pujar
- Department of Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Emma Matthews
- Atkinson-Morley Neuromuscular Centre, Department of Neurology, St George's University Hospitals NHS Foundation Trust, London, UK; Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.
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7
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Xu Y, Jia G, Li T, Zhou Z, Luo Y, Chao Y, Bao J, Su Z, Qu Q, Li D. Molecular insights into biogenesis of glycosylphosphatidylinositol anchor proteins. Nat Commun 2022; 13:2617. [PMID: 35551457 PMCID: PMC9098846 DOI: 10.1038/s41467-022-30250-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/22/2022] [Indexed: 02/08/2023] Open
Abstract
Eukaryotic cells are coated with an abundance of glycosylphosphatidylinositol anchor proteins (GPI-APs) that play crucial roles in fertilization, neurogenesis, and immunity. The removal of a hydrophobic signal peptide and covalent attachment of GPI at the new carboxyl terminus are catalyzed by an endoplasmic reticulum membrane GPI transamidase complex (GPI-T) conserved among all eukaryotes. Here, we report the cryo-electron microscopy (cryo-EM) structure of the human GPI-T at a global 2.53-Å resolution, revealing an equimolar heteropentameric assembly. Structure-based mutagenesis suggests a legumain-like mechanism for the recognition and cleavage of proprotein substrates, and an endogenous GPI in the structure defines a composite cavity for the lipid substrate. This elongated active site, stemming from the membrane and spanning an additional ~22-Å space toward the catalytic dyad, is structurally suited for both substrates which feature an amphipathic pattern that matches this geometry. Our work presents an important step towards the mechanistic understanding of GPI-AP biosynthesis. GPI-T catalyzes the committed step in GPI anchor protein biogenesis. Here, Xu et al. report the cryo-EM structure of the human GPI-T, revealing critical elements within an elongated, shared active site which is topologically arranged for substrate specificity.
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Affiliation(s)
- Yidan Xu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), 320 Yueyang Road, 200030, Shanghai, China
| | - Guowen Jia
- State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610044, Chengdu, China
| | - Tingting Li
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), 320 Yueyang Road, 200030, Shanghai, China
| | - Zixuan Zhou
- Shanghai Stomatological Hospital, School of Stomatology, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Department of Systems Biology for Medicine, Fudan University, 200032, Shanghai, China
| | - Yitian Luo
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), 320 Yueyang Road, 200030, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, 201210, Shanghai, China
| | - Yulin Chao
- Shanghai Stomatological Hospital, School of Stomatology, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Department of Systems Biology for Medicine, Fudan University, 200032, Shanghai, China
| | - Juan Bao
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), 320 Yueyang Road, 200030, Shanghai, China
| | - Zhaoming Su
- State Key Laboratory of Biotherapy and Cancer Center, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, 610044, Chengdu, China.
| | - Qianhui Qu
- Shanghai Stomatological Hospital, School of Stomatology, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Department of Systems Biology for Medicine, Fudan University, 200032, Shanghai, China.
| | - Dianfan Li
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), 320 Yueyang Road, 200030, Shanghai, China.
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Paprocka J, Hutny M, Hofman J, Tokarska A, Kłaniewska M, Szczałuba K, Stembalska A, Jezela-Stanek A, Śmigiel R. Spectrum of Neurological Symptoms in Glycosylphosphatidylinositol Biosynthesis Defects: Systematic Review. Front Neurol 2022; 12:758899. [PMID: 35058872 PMCID: PMC8763846 DOI: 10.3389/fneur.2021.758899] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Mutations of genes involved in the synthesis of glycosylphosphatidylinositol and glycosylphosphatidylinositol-anchored proteins lead to rare syndromes called glycosylphosphatidylinositol-anchored proteins biosynthesis defects. Alterations of their structure and function in these disorders impair often fundamental processes in cells, resulting in severe clinical image. This study aimed to provide a systematic review of GPIBD cases reports published in English-language literature. Methods: The browsing of open-access databases (PubMed, PubMed Central. and Medline) was conducted, followed by statistical analysis of gathered information concerning neurological symptomatology. The inclusion criteria were: studies on humans, age at onset (<18 y.o.), and report of GPIBD cases with adequate data on the genetic background and symptomatology. Exclusion criteria were: publication type (manuscripts, personal communication, review articles); reports of cases of GPI biosynthesis genes mutations in terms of other disorders; reports of GPIBD cases concentrating on non-neurological symptoms; or articles concentrating solely on the genetic issues of GPI biosynthesis. Risk of bias was assessed using Joanna Brigs Institute Critical Appraisal Checklists. Data synthesis was conducted using STATISTICA 13.3.721.1 (StatSoft Polska Sp. z.o.o.). Used tests were chi-square, Fisher's exact test (for differences in phenotype), and Mann-Whitney U test (for differences in onset of developmental delay). Results: Browsing returned a total of 973 articles which, after ruling out the repetitions and assessing the inclusion and exclusion criteria, led to final inclusion of 77 articles (337 GPIBD cases) in the analysis. The main outcomes were prevalence of neurological symptoms, onset and semiology of seizures and their response to treatment, and onset of developmental delay. Based on this data a synthesis of phenotypical differences between the groups of GPIBD cases and the general GPIBD cases population was made. Discussion: A synthetical analysis of neurological components in clinical image of GPIBD patients was presented. It highlights the main features of these disorders, which might be useful in clinical practice for consideration in differential diagnosis with children presenting with early-onset seizures and developmental delay. The limitation of this review is the scarcity of the specific data in some reports, concerning the semiology and onset of two main features of GPIBD.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Michał Hutny
- Students' Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Jagoda Hofman
- Students' Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Agnieszka Tokarska
- Department of Pediatrics and Developmental Age Neurology, Upper Silesian Child Health Centre, Katowice, Poland
| | | | - Krzysztof Szczałuba
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | | | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - Robert Śmigiel
- Department of Pediatrics, Medical University of Wroclaw, Wroclaw, Poland
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9
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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.).
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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
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10
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Bayat A, Pendziwiat M, Obersztyn E, Goldenberg P, Zacher P, Döring JH, Syrbe S, Begtrup A, Borovikov A, Sharkov A, Karasińska A, Giżewska M, Mitchell W, Morava E, Møller RS, Rubboli G. Deep-Phenotyping the Less Severe Spectrum of PIGT Deficiency and Linking the Gene to Myoclonic Atonic Seizures. Front Genet 2021; 12:663643. [PMID: 34046058 PMCID: PMC8148046 DOI: 10.3389/fgene.2021.663643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
The two aims of this study were (i) to describe and expand the phenotypic spectrum of PIGT deficiency in affected individuals harboring the c.1582G>A; p.Val528Met or the c.1580A > G; p.Asn527Ser variant in either homozygous or compound heterozygous state, and (ii) to identify potential genotype-phenotype correlations and any differences in disease severity among individuals with and without the PIGT variants. The existing literature was searched to identify individuals with and without the two variants. A detailed phenotypic assessment was performed of 25 individuals (both novel and previously published) with the two PIGT variants. We compared severity of disease between individuals with and without these PIGT variants. Twenty-four individuals carried the PIGT variant Val528Met in either homozygous or compound heterozygous state, and one individual displayed the Asn527Ser variant in a compound heterozygous state. Disease severity in the individual with the Asn527Ser variant was compatible with that in the individuals harboring the Val528Met variant. While individuals without the Asn527Ser or Val528Met variant had focal epilepsy, profound developmental delay (DD), and risk of premature death, those with either of the two variants had moderate to severe DD and later onset of epilepsy with both focal and generalized seizures. Individuals homozygous for the Val528Met variant generally became seizure-free on monotherapy with antiepileptic drugs, compared to other PIGT individuals who were pharmaco-resistant. Two patients were diagnosed with myoclonic-atonic seizures, and a single patient was diagnosed with eyelid myoclonia. Our comprehensive analysis of this large cohort of previously published and novel individuals with PIGT variants broadens the phenotypical spectrum and shows that both Asn527Ser and Val528Met are associated with a milder phenotype and less severe outcome. Our data show that PIGT is a new candidate gene for myoclonic atonic epilepsy. Our genotype-phenotype correlation will be useful for future genetic counseling. Natural history studies of this mild spectrum of PIGT-related disorder may shed light on hitherto unknown aspects of this rare disorder.
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Affiliation(s)
- Allan Bayat
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.,Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Manuela Pendziwiat
- Department of Neuropediatrics, Children's Hospital, University Medical Center Schleswig-Holstein, University of Kiel, Kiel, Germany.,Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Ewa Obersztyn
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Paula Goldenberg
- Division of Medical Genetics, Massachusetts General Hospital, Boston, MA, United States
| | - Pia Zacher
- The Saxon Epilepsy Center Kleinwachau, Radeberg, Germany
| | - Jan Henje Döring
- Department of General Pediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Steffen Syrbe
- Department of General Pediatrics, Division of Child Neurology and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | | | | | - Artem Sharkov
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University, Moscow, Russia
| | - Aneta Karasińska
- Department of Dermatology, The Nicolas Copernicus State Hospital, Koszalin, Poland
| | - Maria Giżewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University, Szczecin, Poland
| | - Wendy Mitchell
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Eva Morava
- Department of Clinical Genomics, Laboratory of Medicine and Pathology, Center for Individualized Medicine, Mayo Clinic, Rochester, MN, United States
| | - Rikke S Møller
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark.,Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Guido Rubboli
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark.,Department of Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
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11
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Sai Chandar D, Krishna Chaithanya B, Prashanthi M. Homozygous Phosphatidylinositol Glycan Class T Mutation in an Indian Girl With Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome 3. Cureus 2021; 13:e14727. [PMID: 34084664 PMCID: PMC8163346 DOI: 10.7759/cureus.14727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Multiple congenital anomalies-hypotonia-seizures syndrome 3 (MCAHS3) is a rare genetic disorder, characterized by infantile-onset epilepsy, hypotonia, global developmental delay, dysmorphic features, and variable congenital anomalies involving the cardiac, skeletal, and genitourinary systems. It is caused by the homozygous or compound heterozygous mutation in the phosphatidylinositol glycan class T (PIGT) gene. Only fewer cases were reported in the literature till now. We described a PIGT mutation in an Indian girl with global developmental delay, infantile-onset seizures, hypotonia, and facial dysmorphism. This case will help to expand the clinical spectrum of PIGT mutation.
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Affiliation(s)
- Dudipala Sai Chandar
- Pediatric Neurology, Star Women and Children Hospital, Karim Nagar, IND.,Pediatrics, Prathima Institute of Medical Sciences, Karim Nagar, IND
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12
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Chun MJ, Moon YS, Jang WR, Chae JH, Kwon YS. Neonatal-Onset PIGT Encephalopathy: A Rare Korean Case with Hypophosphatasia. ANNALS OF CHILD NEUROLOGY 2021. [DOI: 10.26815/acn.2021.00444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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13
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Molecular analysis of GPI-anchor biosynthesis pathway genes in rat strains used for the Pig-a gene mutation assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2020; 858-860:503256. [DOI: 10.1016/j.mrgentox.2020.503256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/05/2020] [Accepted: 09/11/2020] [Indexed: 11/20/2022]
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14
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Höchsmann B, Murakami Y, Osato M, Knaus A, Kawamoto M, Inoue N, Hirata T, Murata S, Anliker M, Eggermann T, Jäger M, Floettmann R, Höllein A, Murase S, Ueda Y, Nishimura JI, Kanakura Y, Kohara N, Schrezenmeier H, Krawitz PM, Kinoshita T. Complement and inflammasome overactivation mediates paroxysmal nocturnal hemoglobinuria with autoinflammation. J Clin Invest 2020; 129:5123-5136. [PMID: 31430258 DOI: 10.1172/jci123501] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/16/2019] [Indexed: 12/16/2022] Open
Abstract
Patients with paroxysmal nocturnal hemoglobinuria (PNH) have a clonal population of blood cells deficient in glycosylphosphatidylinositol-anchored (GPI-anchored) proteins, resulting from a mutation in the X-linked gene PIGA. Here we report on a set of patients in whom PNH results instead from biallelic mutation of PIGT on chromosome 20. These PIGT-PNH patients have clinically typical PNH, but they have in addition prominent autoinflammatory features, including recurrent attacks of aseptic meningitis. In all these patients we find a germ-line point mutation in one PIGT allele, whereas the other PIGT allele is removed by somatic deletion of a 20q region comprising maternally imprinted genes implicated in myeloproliferative syndromes. Unlike in PIGA-PNH cells, GPI is synthesized in PIGT-PNH cells and, since its attachment to proteins is blocked, free GPI is expressed on the cell surface. From studies of patients' leukocytes and of PIGT-KO THP-1 cells we show that, through increased IL-1β secretion, activation of the lectin pathway of complement and generation of C5b-9 complexes, free GPI is the agent of autoinflammation. Eculizumab treatment abrogates not only intravascular hemolysis, but also autoinflammation. Thus, PIGT-PNH differs from PIGA-PNH both in the mechanism of clonal expansion and in clinical manifestations.
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Affiliation(s)
- Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Transfusion Service and University Hospital Ulm, Ulm, Germany
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Makiko Osato
- Research Institute for Microbial Diseases and.,Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Michi Kawamoto
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Norimitsu Inoue
- Department of Tumor Immunology, Osaka International Cancer Institute, Osaka, Japan
| | | | - Shogo Murata
- Research Institute for Microbial Diseases and.,Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
| | - Thomas Eggermann
- Institute for Human Genetics,Medical Faculty, RWTH University Aachen, Aachen, Germany
| | - Marten Jäger
- Department of Medical Genetics, Charite Hospital, University of Berlin, Berlin, Germany
| | - Ricarda Floettmann
- Department of Medical Genetics, Charite Hospital, University of Berlin, Berlin, Germany
| | | | - Sho Murase
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasutaka Ueda
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Jun-Ichi Nishimura
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuzuru Kanakura
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Nobuo Kohara
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | | | - Peter M Krawitz
- Institute for Genomic Statistics and Bioinformatics, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases and.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
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15
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Okai H, Ikema R, Nakamura H, Kato M, Araki M, Mizuno A, Ikeda A, Renbaum P, Segel R, Funato K. Cold‐sensitive phenotypes of a yeast null mutant of ARV1 support its role as a GPI flippase. FEBS Lett 2020; 594:2431-2439. [DOI: 10.1002/1873-3468.13843] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Haruka Okai
- School of Applied Biological Science Hiroshima University Higashi‐Hiroshima Japan
| | - Ryoko Ikema
- Graduate School of Integrated Sciences for Life Hiroshima University Higashi‐Hiroshima Japan
| | - Hiroki Nakamura
- Graduate School of Biosphere Science Hiroshima University Higashi‐Hiroshima Japan
| | - Mei Kato
- Graduate School of Integrated Sciences for Life Hiroshima University Higashi‐Hiroshima Japan
| | - Misako Araki
- Graduate School of Integrated Sciences for Life Hiroshima University Higashi‐Hiroshima Japan
| | - Ayumi Mizuno
- School of Applied Biological Science Hiroshima University Higashi‐Hiroshima Japan
| | - Atsuko Ikeda
- Graduate School of Biosphere Science Hiroshima University Higashi‐Hiroshima Japan
| | - Paul Renbaum
- Medical Genetics Institute Shaare Zedek Medical Center Jerusalem Israel
| | - Reeval Segel
- Medical Genetics Institute Shaare Zedek Medical Center Jerusalem Israel
| | - Kouichi Funato
- School of Applied Biological Science Hiroshima University Higashi‐Hiroshima Japan
- Graduate School of Integrated Sciences for Life Hiroshima University Higashi‐Hiroshima Japan
- Graduate School of Biosphere Science Hiroshima University Higashi‐Hiroshima Japan
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16
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Analyzing clinical and genetic characteristics of a cohort with multiple congenital anomalies-hypotonia-seizures syndrome (MCAHS). Orphanet J Rare Dis 2020; 15:78. [PMID: 32220244 PMCID: PMC7099766 DOI: 10.1186/s13023-020-01365-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/18/2020] [Indexed: 12/28/2022] Open
Abstract
Objective To summarize and extend the phenotypic characterization of Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome, and to discuss genotype-phenotype correlations. Methods Collecting clinical information of 17 patients with pathogenic variants in PIGN, PIGA, and PIGT. Genetic studies were performed on all patients. Results There were 7 patients with 15 PIGN mutations (one patient carrying 3 mutations), 8 patients with 8 PIGA mutations, and 2 patients with 5 PIGT mutations (one patient carrying 3 mutations). All patients had epilepsy and developmental delay, with 71% of them showed hypotonia. And among these patients’ various seizure types, the focal seizure was the most common one. Eighty-two percent patients showed a significant relationship between seizures and fever. Serum ALP was elevated in one patient with PIGN mutations and in two patients with PIGA mutations. Brain MRI showed enlarged subarachnoid space in 56% of patients. Some other different characteristics had also been found in our patients: First, atypical absence seizures presented in three patients with PIGN mutations; Second, diffuse slow waves mixed with focal or multifocal discharges of interictal EEG in 88% cases with PIGA-deficient; Third, phenotypes of seven out of eight patients with PIGA mutations were difficult to be classified as severe or less severe group; Last, mild neurological symptoms and developmental status rather than severe conditions occurred in one patient with PIGT mutations. Conclusion With epilepsy, developmental delay, and/or hypotonia as common features, the knowledge of MCAHS in terms of phenotype and genotype has been expanded. In cases with PIGN-deficient, we expanded the types of atypical absence seizures, and described one patient with elevated serum ALP. Focal seizures with diffuse slow waves mixed with focal or multifocal discharges on EEG rather than infantile spasms with hypsarrhythmia, which as previously reported were often seen in our patients with PIGA mutations. The classifications of phenotypes caused by PIGA mutations should be more continuous than discrete. The mild phenotype of one patient with PIGT mutations expanded the clinical presentation of MCAHS3.
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17
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Mierzewska H, Jezela-Stanek A. Is leucodystrophy really a feature of PIGT-CDG? Neuropathol Appl Neurobiol 2020; 46:615-616. [PMID: 32058618 DOI: 10.1111/nan.12609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 01/03/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Hanna Mierzewska
- Department of Child and Adolescent Neurology, Institute of Mother and Child, Warsaw, Poland
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
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18
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Abstract
At least 150 human proteins are glycosylphosphatidylinositol-anchored proteins (GPI-APs). The protein moiety of GPI-APs lacking transmembrane domains is anchored to the plasma membrane with GPI covalently attached to the C-terminus. The GPI consists of the conserved core glycan, phosphatidylinositol and glycan side chains. The entire GPI-AP is anchored to the outer leaflet of the lipid bilayer by insertion of fatty chains of phosphatidylinositol. Because of GPI-dependent membrane anchoring, GPI-APs have some unique characteristics. The most prominent feature of GPI-APs is their association with membrane microdomains or membrane rafts. In the polarized cells such as epithelial cells, many GPI-APs are exclusively expressed in the apical surfaces, whereas some GPI-APs are preferentially expressed in the basolateral surfaces. Several GPI-APs act as transcytotic transporters carrying their ligands from one compartment to another. Some GPI-APs are shed from the membrane after cleavage within the GPI by a GPI-specific phospholipase or a glycosidase. In this review, I will summarize the current understanding of GPI-AP biosynthesis in mammalian cells and discuss examples of GPI-dependent functions of mammalian GPI-APs.
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Affiliation(s)
- Taroh Kinoshita
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, Japan
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19
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Larsen KB, Bayat A, Møller RS, Maroun LL, Lund EL. First report of the neuropathological findings in a patient with leukodystrophy and compound heterozygous variants in the
PIGT
gene. Neuropathol Appl Neurobiol 2019; 45:732-735. [DOI: 10.1111/nan.12557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/23/2019] [Indexed: 11/28/2022]
Affiliation(s)
- K. B. Larsen
- Department of Pathology University Hospital of Copenhagen Rigshospitalet Denmark
- Department of Neuropathology and Ocular Pathology John Radcliffe Hospital Oxford University Hospital Oxford UK
| | - A. Bayat
- Department of Pediatrics University Hospital of Copenhagen Rigshospitalet Denmark
- Danish Epilepsy Centre Dianalund Denmark
| | - R. S. Møller
- Danish Epilepsy Centre Dianalund Denmark
- Department of Regional Health Research University of Southern Denmark Odense Denmark
| | - L. L. Maroun
- Department of Pathology University Hospital of Copenhagen Rigshospitalet Denmark
| | - E. L. Lund
- Department of Pathology University Hospital of Copenhagen Rigshospitalet Denmark
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20
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Komath SS, Singh SL, Pratyusha VA, Sah SK. Generating anchors only to lose them: The unusual story of glycosylphosphatidylinositol anchor biosynthesis and remodeling in yeast and fungi. IUBMB Life 2019; 70:355-383. [PMID: 29679465 DOI: 10.1002/iub.1734] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/16/2018] [Accepted: 02/22/2018] [Indexed: 02/06/2023]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) are present ubiquitously at the cell surface in all eukaryotes. They play a crucial role in the interaction of the cell with its external environment, allowing the cell to receive signals, respond to challenges, and mediate adhesion. In yeast and fungi, they also participate in the structural integrity of the cell wall and are often essential for survival. Roughly four decades after the discovery of the first GPI-APs, this review provides an overview of the insights gained from studies of the GPI biosynthetic pathway and the future challenges in the field. In particular, we focus on the biosynthetic pathway in Saccharomyces cerevisiae, which has for long been studied as a model organism. Where available, we also provide information about the GPI biosynthetic steps in other yeast/ fungi. Although the core structure of the GPI anchor is conserved across organisms, several variations are built into the biosynthetic pathway. The present Review specifically highlights these variations and their implications. There is growing evidence to suggest that several phenotypes are common to GPI deficiency and should be expected in GPI biosynthetic mutants. However, it appears that several phenotypes are unique to a specific step in the pathway and may even be species-specific. These could suggest the points at which the GPI biosynthetic pathway intersects with other important cellular pathways and could be points of regulation. They could be of particular significance in the study of pathogenic fungi and in identification of new and specific antifungal drugs/ drug targets. © 2018 IUBMB Life, 70(5):355-383, 2018.
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Affiliation(s)
| | - Sneh Lata Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Sudisht Kumar Sah
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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21
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Bayat A, Knaus A, Juul AW, Dukic D, Gardella E, Charzewska A, Clement E, Hjalgrim H, Hoffman-Zacharska D, Horn D, Horton R, Hurst JA, Josifova D, Larsen LHG, Lascelles K, Obersztyn E, Pagnamenta A, Pal DK, Pendziwiat M, Ryten M, Taylor J, Vogt J, Weber Y, Krawitz PM, Helbig I, Kini U, Møller RS. PIGT-CDG, a disorder of the glycosylphosphatidylinositol anchor: description of 13 novel patients and expansion of the clinical characteristics. Genet Med 2019; 21:2216-2223. [DOI: 10.1038/s41436-019-0512-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/25/2019] [Indexed: 12/20/2022] Open
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22
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Mason S, Castilla-Vallmanya L, James C, Andrews PI, Balcells S, Grinberg D, Kirk EP, Urreizti R. Case report of a child bearing a novel deleterious splicing variant in PIGT. Medicine (Baltimore) 2019; 98:e14524. [PMID: 30813157 PMCID: PMC6407924 DOI: 10.1097/md.0000000000014524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Trio family-based whole exome sequencing (WES) is a powerful tool in the diagnosis of rare neurodevelopmental diseases, even in patients with the unclear diagnosis. There have been previous reports of variants in the phosphatidylinositol glycan anchor biosynthesis class T (PIGT) gene associated with multiple congenital anomalies, with a total of 14 affected individuals across 8 families. PATIENT CONCERNS An 18-month-old boy of Greek ancestry presented with global developmental delay, generalized tonic-clonic seizures, hypotonia, renal cysts, esotropia, bilateral undescended testes, bilateral vesicoureteric reflux, marked cardiac dextroposition, bilateral talipes equinovarus, and dysmorphic features. DIAGNOSIS WES revealed 2 compound heterozygous variants in the PIGT gene, c.[494-2A>G]; [547A>C]/p.[Asp122Glyfs*35]; [Thr183Pro]. The splicing mutation was demonstrated to lead to the skipping of exon 4. INTERVENTIONS Seizures, infections, and other main symptoms were treated. OUTCOMES The patient died at 2 years of age before the molecular diagnosis was achieved. Genetic counseling has been offered to the family. LESSONS Most of the clinical features of the patient are in agreement with the previously described PIGT cases corroborating the usefulness of WES as a diagnostic tool.
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Affiliation(s)
- Samantha Mason
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Laura Castilla-Vallmanya
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, IBUB, Institut de Recerca Sant Joan de Déu (IRSJD), CIBERER, Barcelona, Spain
| | | | | | - Susana Balcells
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, IBUB, Institut de Recerca Sant Joan de Déu (IRSJD), CIBERER, Barcelona, Spain
| | - Daniel Grinberg
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, IBUB, Institut de Recerca Sant Joan de Déu (IRSJD), CIBERER, Barcelona, Spain
| | - Edwin P. Kirk
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia
- NSW Health Pathology East, Genetics Laboratory
- School of Women's and Children's Health, University of New South Wales, Randwick, Sydney, Australia
| | - Roser Urreizti
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, IBUB, Institut de Recerca Sant Joan de Déu (IRSJD), CIBERER, Barcelona, Spain
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23
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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.
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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.
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