Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease and Parkinson's disease. Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.
Animals ; Mice ; Dysbiosis/metabolism* ; Mice, Knockout ; Humans ; Lysosomal Membrane Proteins/genetics* ; Receptors, Scavenger/genetics* ; Gastrointestinal Microbiome ; Myoclonic Epilepsies, Progressive/genetics* ; Vitamin E Deficiency/complications* ; Neurodegenerative Diseases/genetics* ; Bile Acids and Salts/metabolism* ; Male ; Lipid Metabolism ; Intestinal Mucosa/pathology*

Objective: To summarize the phenotypes of epilepsy in patients with MBD5 gene variants. Methods: A total of 9 epileptic patients, who were treated in the Department of Pediatrics, Peking University First Hospital from July 2016 to September 2021 and detected with MBD5 gene pathogenic variants, were enrolled. The features of clinical manifestations, electroencephalogram (EEG), and neuroimaging were analyzed retrospectively. Results: Among 9 patients, 6 were male and 3 were female. Age at seizure onset ranged from 5 to 89 months. Multiple seizure types were observed, including generalized tonic clonic seizures (GTCS) in 7 patients, myoclonic seizures in 5 patients, focal seizures in 5 patients, atypical absence seizures in 3 patients, atonic seizures in 2 patients, myoclonus absence seizures in 1 patient, epileptic spasms in 1 patient, and tonic seizures in 1 patient. There were 8 patients with multiple seizure types, 2 patients with sensitivity to fever and 5 patients with clustering of seizures. Two patients had a history of status epilepticus. All patients had developmental delay before seizure onset. Nine patients had obvious language delay, and 6 patients had autism-like manifestations. Five patients had slow background activity in EEG. Interictal EEG showed abnormal discharges in 9 patients. Brain magnetic resonance imaging (MRI) was normal in all patients. A total of 9 epileptic patients carried MBD5 gene variants, all of them were de novo variants. There were MBD5 gene overall heterozygous deletion in 1 patient, large fragment deletions including MBD5 gene in 3 patients and single nucleotide variations (c.300C>A/p.C100X, c.1775delA/p.N592Tfs*29, c.1759C>T/p.Q587X, c.150_151del/p.Lys51Asnfs*6, c.113+1G>C) in 5 patients. The age at last follow-up ranged from 2 years and 9 months to 11 years and 11 months. At the last follow-up, 2 patients were seizure-free for more than 11 months to 4 years 6 months, 7 patients still had seizures. Conclusions: The initial seizure onset in patients with MBD5 gene variants usually occurs in infancy. Most patients have multiple seizure types. The seizures may be fever sensitive and clustered. Developmental delays, language impairments, and autistic behaviors are common. MBD5 gene variants include single nucleotide variations and fragment deletions. Epilepsy associated with MBD5 gene variants is usually refractory.
Child ; Child, Preschool ; DNA-Binding Proteins/genetics* ; Electroencephalography ; Epilepsies, Myoclonic/genetics* ; Epilepsy/genetics* ; Female ; Fever ; Humans ; Infant ; Male ; Nucleotides ; Phenotype ; Retrospective Studies ; Seizures/genetics*

OBJECTIVE: To analyze the clinical features and genetic variants in two patients with Dravet syndrome (DS). METHODS: Peripheral blood samples of the children and their parents were collected for the extraction of genomic DNA and high-throughput sequencing. Suspected variants were confirmed by Sanger sequencing. RESULTS: By high-throughput sequencing, the two children were found to respectively harbor a c.2135delC frameshifting variant in exon 12 and a c.1522G>T nonsense variant in exon 10 of the SCN1A gene. Both variants were predicted to be pathogenic by bioinformatic analysis. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.2135delC and c.1522G>A variants of the SCN1A gene were predicted to be pathogenic (PVS1+ PS2+ PM2+ PP3). CONCLUSION The variants of the SCN1A gene probably underlay the DS in the patients. Above finding has enriched the variant spectrum and enabled genetic counseling for their families.
Epilepsies, Myoclonic/genetics* ; Genomics ; Humans ; Infant ; Mutation ; NAV1.1 Voltage-Gated Sodium Channel/genetics* ; Pedigree ; Spasms, Infantile/genetics*

Adult ; Humans ; Male ; Myoclonic Epilepsies, Progressive ; diagnostic imaging ; genetics ; therapy ; Nerve Tissue Proteins ; genetics ; Pedigree

OBJECTIVETo determine the type and frequency of SCN1A deletions and duplications among patients with Dravet syndrome (DS).

METHODSFor DS patients in which no mutations of the SCN1A gene were detected by PCR-DNA sequencing, SCN1A deletions and duplications were detected by multiplex ligation-dependent probe amplification (MLPA).

RESULTSIn 680 DS patients, 489 had SCN1A mutations identified by PCR-DNA sequencing. In 191 patients who were negative for the SCN1A PCR-DNA sequencing, 15 (15/191, 7.9%) were detected with heterozygous SCN1A deletions or duplications, which included 14 (14/15, 93.3%) SCN1A deletions and 1 SCN1A duplication. There were 13 types of mutations, including whole SCN1A deletions in 3 patients, partial SCN1A deletions in 11 patients and partial SCN1A duplications in one patient. By testing the parents, 14 mutations were found to be de novo. For the remaining case, no SCN1A deletion or duplication was found in the mother, while the father was not available.

CONCLUSIONApproximately 8% of Chinese patients who were negative for SCN1A mutation by PCR-sequencing have SCN1A deletions or duplications. The MLPA analysis should be considered as an important strategy for such patients. SCN1A deletions are more common than SCN1A duplications among DS patients, and the most common types are whole SCN1A deletions. The majority of SCN1A deletions or duplications are de novo.

Epilepsies, Myoclonic ; genetics ; Female ; Gene Deletion ; Gene Duplication ; Humans ; Infant ; Male ; Multiplex Polymerase Chain Reaction ; NAV1.1 Voltage-Gated Sodium Channel ; genetics

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.
Epilepsies, Myoclonic* ; Genetics, Medical ; Genomics ; Humans ; Male ; Mutation, Missense ; Parents ; Retrospective Studies

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.
Epilepsies, Myoclonic* ; Genetics, Medical ; Genomics ; Humans ; Male ; Mutation, Missense ; Parents ; Retrospective Studies

The Diagnostic Genetics Subcommittee of Korean Association of External Quality Assessment Service conducted two trials in 2015 based on cytogenetics and molecular genetics surveys. A total of 43 laboratories participated in the chromosome surveys, 31 laboratories participated in the fluorescence in situ hybridization surveys, and 133 laboratories participated in the molecular genetics surveys. All except one laboratory showed acceptable results in the cytogenetics surveys. The molecular genetics surveys included the following tests: Mycobacterium tuberculosis detection, hepatitis B and C virus detection and quantification, human papilloma virus genotyping, gene rearrangement tests for leukaemias and lymphomas, genetic tests for JAK2, FMS-like tyrosine kinase 3, nucleophosmin, cancer-associated genes (KRAS, EGFR, KIT, and BRAF), hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), Li-Fraumeni syndrome (TP53), Wilson disease (ATP7B), achondroplasia (FGFR3), hearing loss and deafness (GJB2 ), multiple endocrine neoplasia 2 (RET), Huntington disease, spinocerebellar ataxia, spinal and bulbar muscular atrophy, mitochondrial encephalopathy with lactic acidosis and stroke like episodes, myoclonic epilepsy ragged red fibre, Leber hereditary optic neuropathy, Prader-Willi/Angelman syndrome, Duchenne muscular dystrophy, spinal muscular atrophy, fragile X syndrome (FMR1), apolipoprotein E genotyping, methylenetetrahydrofolate reductase genotyping, ABO genotyping, cytochrome P450 2C9 genotyping, cytochrome P450 2C19 genotyping, and DNA sequencing analysis. The molecular genetics surveys showed excellent results for most of the participants. The external quality assessment program for genetics analysis in 2015 proved to be helpful for continuous education and the evaluation of quality improvement.
Achondroplasia ; Acidosis, Lactic ; Apolipoproteins ; Breast ; Cytochrome P-450 Enzyme System ; Cytogenetics ; Deafness ; Education ; Epilepsies, Myoclonic ; Fluorescence ; fms-Like Tyrosine Kinase 3 ; Fragile X Syndrome ; Gene Rearrangement ; Genetics* ; Hearing Loss ; Hepatitis B ; Hepatolenticular Degeneration ; Humans ; Huntington Disease ; In Situ Hybridization ; Korea* ; Li-Fraumeni Syndrome ; Lymphoma ; Methylenetetrahydrofolate Reductase (NADPH2) ; Molecular Biology ; Multiple Endocrine Neoplasia ; Muscular Atrophy, Spinal ; Muscular Disorders, Atrophic ; Muscular Dystrophy, Duchenne ; Mycobacterium tuberculosis ; Optic Atrophy, Hereditary, Leber ; Ovarian Neoplasms ; Papilloma ; Quality Improvement ; Sequence Analysis, DNA ; Spinocerebellar Ataxias ; Stroke

No abstract available.
Adult ; Anticonvulsants/therapeutic use ; Bone Marrow/*pathology ; Epilepsies, Myoclonic/complications/*diagnosis/drug therapy ; Female ; Gaucher Disease/complications/*diagnosis/drug therapy ; Glucosylceramidase/genetics/therapeutic use ; Humans ; Phenotype ; Point Mutation ; Recurrence

Adult ; Aged ; Chromosome Aberrations ; Epilepsies, Myoclonic ; diagnosis ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree