scholarly journals RYR2 Mutations Are Associated With Benign Epilepsy of Childhood With Centrotemporal Spikes With or Without Arrhythmia

2021 ◽  
Vol 15 ◽  
Author(s):  
Mei-Gang Ma ◽  
Xiao-Rong Liu ◽  
Yuan Wu ◽  
Jie Wang ◽  
Bing-Mei Li ◽  
...  
Keyword(s):  
De Novo ◽  
Arrhythmogenic Right Ventricular Dysplasia ◽  
Polymorphic Ventricular Tachycardia ◽  
Compound Heterozygous ◽  
Endoplasmic Reticulum Membrane ◽  
Missense Mutations ◽  
Unexpected Death ◽  
Sinus Arrhythmia ◽  
Whole Exome ◽  
Benign Epilepsy

RYR2 encodes ryanodine receptor 2 protein (RYR-2) that is mainly located on endoplasmic reticulum membrane and regulates intracellular calcium concentration. The RYR-2 protein is ubiquitously distributed and highly expressed in the heart and brain. Previous studies have identified the RYR2 mutations in the etiology of arrhythmogenic right ventricular dysplasia 2 and catecholaminergic polymorphic ventricular tachycardia. However, the relationship between RYR2 gene and epilepsy is not determined. In this study, we screened for novel genetic variants in a group of 292 cases (families) with benign epilepsy of childhood with centrotemporal spikes (BECTS) by trio-based whole-exome sequencing. RYR2 mutations were identified in five cases with BECTS, including one heterozygous frameshift mutation (c.14361dup/p.Arg4790Pro fs∗6), two heterozygous missense mutations (c.2353G > A/p.Asp785Asn and c.8574G > A/p.Met2858Ile), and two pairs of compound heterozygous mutations (c.4652A > G/p.Asn1551Ser and c.11693T > C/p.Ile3898Thr, c.7469T > C/p.Val2490Ala and c.12770G > A/p.Arg4257Gln, respectively). Asp785Asn was a de novo missense mutation. All the missense mutations were suggested to be damaging by at least three web-based prediction tools. These mutations do not present or at low minor allele frequency in gnomAD database and present statistically higher frequency in the cohort of BECTS than in the control populations of gnomAD. Asp785Asn, Asn1551Ser, and Ile3898Thr were predicted to affect hydrogen bonds with surrounding amino acids. Three affected individuals had arrhythmia (sinus arrhythmia and occasional atrial premature). The two probands with compound heterozygous missense mutations presented mild cardiac structural abnormalities. Strong evidence from ClinGen Clinical Validity Framework suggested an association between RYR2 variants and epilepsy. This study suggests that RYR2 gene is potentially a candidate pathogenic gene of BECTS. More attention should be paid to epilepsy patients with RYR2 mutations, which were associated with arrhythmia and sudden unexpected death in previous reports.

An intronic variant disrupts mRNA splicing and causes FGFR3-related skeletal dysplasia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ting Xu ◽  
Liang Shi ◽  
Weiqian Dai ◽  
Xuefan Gu ◽  
Yongguo Yu ◽  
...  
Keyword(s):  
De Novo ◽  
Clinical Findings ◽  
Recurrent Mutation ◽  
Mrna Splicing ◽  
Additional Patient ◽  
Missense Mutations ◽  
Splicing Variant ◽  
Amino Acid Insertion ◽  
Whole Exome ◽  
Minigene Assay

Abstract Objectives Achondroplasia and hypochondroplasia are the most common forms of disproportionate short stature, of which the vast majority of cases can be attributed to the hotspot missense mutations in the gene FGFR3. Here we presented cases with a novel cryptic splicing variant of FGFR3 gene and aimed to interrogate the variant pathogenicity. Case presentaiton In whole exome sequencing of two patients with hypochondroplasia-like features, a de novo intronic variant c.1075 + 95C>G was identified, predicted to alter mRNA splicing. Minigene assay showed that this intronic variant caused retention of a 90-nucleotide segment of intron 8 in mRNA, resulting in a 30-amino acid insertion at the extracellular domain of the protein. This is the first likely pathogenic splicing variant identified in the FGFR3 gene and was detected in one additional patient among 26 genetically unresolved patients. Conclustions Our results strongly suggest that c.1075 + 95C>G is a recurrent mutation and should be included in genetic testing of FGFR3 especially for those patients with equivocal clinical findings and no exonic mutations identified.

scholarly journals Whole exome sequencing identifies compound heterozygous variants of CR2 gene in monozygotic twin patients with common variable immunodeficiency

2020 ◽  
Vol 8 ◽  
pp. 205031212092265
Author(s):  
Adiratna Mat Ripen ◽  
Hamidah Ghani ◽  
Chai Teng Chear ◽  
Mei Yee Chiow ◽  
Sharifah Nurul Husna Syed Yahya ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Complex Disease ◽  
Monozygotic Twins ◽  
Compound Heterozygous ◽  
Sequencing Analysis ◽  
Missense Mutations ◽  
Upper Respiratory Tract ◽  
Whole Exome ◽  
Tract Infections

Objectives: A pair of female Malay monozygotic twins who presented with recurrent upper respiratory tract infections, hepatosplenomegaly, bronchiectasis and bicytopenia were recruited in this study. Both patients were suspected with primary immunodeficiency diseases. However, the definite diagnosis was not clear due to complex disease phenotypes. The objective of this study was to identify the causative gene mutation in these patients. Methods: Lymphocyte subset enumeration test and whole exome sequencing were performed. Results: We identified a compound heterozygous CR2 mutation (c.1916G>A and c.2012G>A) in both patients. These variants were then confirmed using Sanger sequencing. Conclusion: Whole exome sequencing analysis of the monozygotic twins revealed compound heterozygous missense mutations in CR2.

scholarly journals Genetic, Phenotypic, and Interferon Biomarker Status in ADAR1-Related Neurological Disease

2017 ◽  
Vol 48 (03) ◽  
pp. 166-184 ◽  
Author(s):  
Gillian Rice ◽  
Naoki Kitabayashi ◽  
Magalie Barth ◽  
Tracy Briggs ◽  
Annabel Burton ◽  
...  
Keyword(s):  
Neurological Disease ◽  
De Novo ◽  
Phenotypic Variability ◽  
Spastic Paraparesis ◽  
Dominant Negative ◽  
Compound Heterozygous ◽  
Motor Disorder ◽  
Type I ◽  
Missense Mutations ◽  
Dominant Negative Mutation

AbstractWe investigated the genetic, phenotypic, and interferon status of 46 patients from 37 families with neurological disease due to mutations in ADAR1. The clinicoradiological phenotype encompassed a spectrum of Aicardi–Goutières syndrome, isolated bilateral striatal necrosis, spastic paraparesis with normal neuroimaging, a progressive spastic dystonic motor disorder, and adult-onset psychological difficulties with intracranial calcification. Homozygous missense mutations were recorded in five families. We observed a p.Pro193Ala variant in the heterozygous state in 22 of 23 families with compound heterozygous mutations. We also ascertained 11 cases from nine families with a p.Gly1007Arg dominant-negative mutation, which occurred de novo in four patients, and was inherited in three families in association with marked phenotypic variability. In 50 of 52 samples from 34 patients, we identified a marked upregulation of type I interferon-stimulated gene transcripts in peripheral blood, with a median interferon score of 16.99 (interquartile range [IQR]: 10.64–25.71) compared with controls (median: 0.93, IQR: 0.57–1.30). Thus, mutations in ADAR1 are associated with a variety of clinically distinct neurological phenotypes presenting from early infancy to adulthood, inherited either as an autosomal recessive or dominant trait. Testing for an interferon signature in blood represents a useful biomarker in this context.

scholarly journals Case Report: Novel mutations in TBC1D24 are associated with autosomal dominant tonic-clonic and myoclonic epilepsy and recessive Parkinsonism, psychosis, and intellectual disability

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 553 ◽  
Author(s):  
Erika Banuelos ◽  
Keri Ramsey ◽  
Newell Belnap ◽  
Malavika Krishnan ◽  
Chris D. Balak ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Autosomal Dominant ◽  
Epileptic Encephalopathy ◽  
Myoclonic Epilepsy ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Single Family ◽  
Whole Exome ◽  
Neurological Phenotype ◽  
Syndromic Hearing Loss

Mutations disrupting presynaptic protein TBC1D24 are associated with a variable neurological phenotype, including DOORS syndrome, myoclonic epilepsy, early-infantile epileptic encephalopathy, and non-syndromic hearing loss. In this report, we describe a family segregating autosomal dominant epilepsy, and a 37-year-old Caucasian female with a severe neurological phenotype including epilepsy, Parkinsonism, psychosis, visual and auditory hallucinations, gait ataxia and intellectual disability. Whole exome sequencing revealed two missense mutations in the TBC1D24 gene segregating within this family (c.1078C>T; p.Arg360Cys and c.404C>T; p.Pro135Leu). The female proband who presents with a severe neurological phenotype carries both of these mutations in a compound heterozygous state. The p.Pro135Leu variant, however, is present in the proband’s mother and sibling as well, and is consistent with an autosomal dominant pattern linked to tonic-clonic and myoclonic epilepsy. In conclusion, we describe a single family in which TBC1D24 mutations cause expanded dominant and recessive phenotypes. In addition, we discuss and highlight that some variants in TBC1D24 might cause a dominant susceptibility to epilepsy

scholarly journals Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – A case report

2019 ◽  
Author(s):  
Sofia Thunström ◽  
Markus Axelsson
Keyword(s):  
Case Report ◽  
Peripheral Neuropathy ◽  
De Novo ◽  
Age Of Onset ◽  
De Novo Mutation ◽  
Missense Mutations ◽  
Dural Ectasia ◽  
Whole Exome ◽  
Demyelinating Peripheral Neuropathy ◽  
Multiple Cysts

Abstract Background: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. Case Presentation: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686T>G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. Conclusions: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes. Keywords: Leukoencephalopathia, demyelinating peripheral neuropathy, dural ectasia explained, de novo mutation, the SAMD9L gene.

scholarly journals Mapping Autosomal Recessive Intellectual Disability: Combined Microarray and Exome Sequencing Identifies 26 Novel Candidate Genes in 192 Consanguineous Families

2016 ◽  
Author(s):  
Ricardo Harripaul ◽  
Nasim Vasli ◽  
Anna Mikhailov ◽  
Muhammad Arshad Rafiq ◽  
Kirti Mittal ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Autosomal Recessive ◽  
De Novo ◽  
Clinical Diagnostics ◽  
High Yield ◽  
Disease Genes ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Whole Exome

Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations(ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7,andUSP44),and missense mutations include the first reports of variants inBDNForTET1associated with ID. The genes identified also showed overlap withde novogene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.

scholarly journals Identification of DNAH6 mutations in infertile men with multiple morphological abnormalities of the sperm flagella

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chaofeng Tu ◽  
Hongchuan Nie ◽  
Lanlan Meng ◽  
Shimin Yuan ◽  
Wenbin He ◽  
...  
Keyword(s):  
Compound Heterozygous ◽  
Missense Mutations ◽  
Transmission Electron Microscopy Analysis ◽  
Chinese Families ◽  
Morphological Abnormalities ◽  
Recessive Mutations ◽  
Transmission Electron ◽  
Whole Exome ◽  
Electron Microscopy Analysis ◽  
Reproductive Counseling

Abstract Male infertility due to spermatogenesis defects affects millions of men worldwide. However, the genetic etiology of the vast majority remains unclear. Here we describe three men with primary infertility due to multiple morphological abnormalities of the sperm flagella (MMAF) from two unrelated Han Chinese families. We performed whole-exome sequencing (WES) and Sanger sequencing on the proband of family 1, and found that he carried novel compound heterozygous missense mutations in dynein axonemal heavy chain 6 (DNAH6) that resulted in the substitution of a conserved amino acid residue and co-segregated with the MMAF phenotype in this family. Papanicolaou staining and transmission electron microscopy analysis revealed morphological and ultrastructural abnormalities in the sperm flagella in carriers of these genetic variants. Immunostaining experiments showed that DNAH6 was localized in the sperm tail. This is the first report identifying novel recessive mutations in DNAH6 as a cause of MMAF. These findings expand the spectrum of known MMAF mutations and phenotypes and provide information that can be useful for genetic and reproductive counseling of MMAF patients.

scholarly journals Frequent germline mutations of HAVCR2 in sporadic subcutaneous panniculitis-like T-cell lymphoma

2019 ◽  
Vol 3 (4) ◽  
pp. 588-595 ◽  
Author(s):  
Chantana Polprasert ◽  
Yasuhide Takeuchi ◽  
Nobuyuki Kakiuchi ◽  
Kenichi Yoshida ◽  
Thamathorn Assanasen ◽  
...  
Keyword(s):  
T Cell ◽  
Somatic Mutations ◽  
Cell Lymphoma ◽  
Germline Mutations ◽  
T Cell Lymphoma ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Whole Exome ◽  
History Of ◽  
Underlying Diseases

Abstract Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare subtype of peripheral T-cell lymphoma affecting younger patients and associated with hemophagocytic lymphohistiocytosis. To clarify the molecular pathogenesis of SPTCL, we analyzed paired tumor and germline DNAs from 13 patients by whole-exome sequencing. All cases were Asians and were phenotypically sporadic with no family history of SPTCL. Consistent with a recent report, germline mutations in HAVCR2, encoding T-cell immunoglobulin mucin 3 (TIM3), were identified in 11 of 13 (85%) cases. All mutated cases were primary SPTCL, whereas the 2 cases without mutation were secondary SPTCL associated with underlying diseases, including viral infection and autoimmune disease. Ten patients harbored homozygous p.Y82C mutations, and 1 showed compound heterozygous mutations (p.Y82C and p.T101I). Both missense mutations altered highly conserved residues located in the extracellular immunoglobulin variable–like domain. According to the Genome Aggregation Database of >138 500 general individuals, both mutations were documented with minor allele frequencies < 0.007, indicating remarkable enrichment of these HAVCR2 alleles in SPTCL. SPTCL cells also harbored somatic mutations (6.2 per patient) that are frequently identified in genes associated with epigenetic regulation and signal transduction. In conclusion, individuals harboring biallelic HAVCR2 (TIM3) germline mutations were highly susceptible to sporadic SPTCL, which was also associated with clonal somatic mutations.

scholarly journals Whole-exome sequencing of de novo genetic variants in a Chinese family with a sporadic case of congenital nonsyndromic hearing loss

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 61
Author(s):  
Sijing Hu ◽  
Hao Zhang ◽  
Yunqiang Liu ◽  
Mohan Liu ◽  
Jingjing Li ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Genetic Variants ◽  
Cellular Localization ◽  
De Novo ◽  
Copy Number Variations ◽  
Occurrence Rate ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Functional Assay ◽  
Whole Exome

Background: We examined the genetic variants of a Chinese family with a 22-month-old infant with sporadic non-syndromic sensorineural hearing loss (NSHL). Methods: The whole-exome sequence data in the family, especially the de novo variants presented in the patient, were analyzed and the effect of the disease-causing genetic variants on the protein expression level and cellular localization were examined by cell-based functional assay. Results: The infant had no known NSHL-causing variants, except two compound heterozygous variants in connexin26 gene GJB2; one was the c.79G>A, c.341A>G haplotype from the asymptomatic mother which was benign, and the other was a de novo pathogenic c.262G>C (p.A88P). In vitro, GJB2 with c.262G>C was weakly expressed and displayed a punctate distribution in the cytoplasm and cytomembrane, while wild type GJB2 was robustly expressed in the cytomembrane. We deduced that the de novo pathogenic GJB2 c.262G>C exacerbated loss-of-function in the context of leaky variants c.79G>A, c.341A>G in the patient. Interestingly, further analysis of exome sequences revealed that the occurrence of de novo pathogenic variants in the infant was frequent. Among the total~47,000 variants, 143 were de novo in the patient, whereas among all 74 variants predicted to be pathogenic/likely pathogenic, 21 were heterozygous and two were homozygous de novo. The occurrence rate of de novo deleterious variants was much higher (31.1%, 23/74) than that in total (0.34%, 143/47,000). It is notable that most genes with de novo deleterious variants were environment-sensitive, such as GJB2, MNK1, MNK2, MUC4, RAD21 and DNA copy number variations. Conclusions: The full picture of genetic variants in the exome might help us to interpret the NSHL-causing variants. More research is needed into the causes of de novo deleterious variants and gene-environment interactions in congenital NSHL.

scholarly journals Accurate interpretation of genetic variants in sudden unexpected death in infancy by trio-targeted gene-sequencing panel analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keita Shingu ◽  
Takehiko Murase ◽  
Takuma Yamamoto ◽  
Yuki Abe ◽  
Yoriko Shinba ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Cause Of Death ◽  
Genetic Variants ◽  
De Novo ◽  
Sudden Unexpected Death ◽  
Compound Heterozygous ◽  
Unexpected Death ◽  
Accurate Interpretation ◽  
Clinically Significant ◽  
Targeted Gene Sequencing

AbstractIn sudden unexpected death in infancy cases, postmortem genetic analysis with next-generation sequencing potentially can extract candidate genes associated with sudden death. However, it is difficult to accurately interpret the clinically significant genetic variants. The study aim was to conduct trio analysis of cases of sudden unexpected death in infancy and their parents to more accurately interpret the clinically significant disease-associated gene variants associated with cause of death. From the TruSight One panel targeting 4813 genes we extracted candidate genetic variants of 66 arrhythmia-, 63 inherited metabolic disease-, 81 mitochondrial disease-, and 6 salt-losing tubulopathy-related genes in 7 cases and determined if they were de novo or parental-derived variants. Thirty-four parental-derived variants and no de novo variants were found, but none appeared to be related to the cause of death. Using trio analysis and an in silico algorithm to analyze all 4813 genes, we identified OBSCN of compound heterozygous and HCCS of hemizygous variants as new candidate genetic variants related to cause of death. Genetic analysis of these deceased infants and their living parents can provide more accurate interpretation of the clinically significant genetic variants than previously possible and help confirm the cause of death.

Sign in / Sign up

Export Citation Format

Share Document