Novel compound heterozygous EPG5 mutations consisted with a missense mutation and a microduplication in the exon 1 region identified in a Japanese patient with Vici syndrome

2018 ◽  
Vol 176 (12) ◽  
pp. 2803-2807 ◽  
Author(s):  
Shino Shimada ◽  
Kyoko Hirasawa ◽  
Akiko Takeshita ◽  
Hidetsugu Nakatsukasa ◽  
Keiko Yamamoto-Shimojima ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Japanese Patient ◽  
Compound Heterozygous ◽  
Exon 1

Novel compound heterozygous mutations identified by whole exome sequencing in a Japanese patient with geroderma osteodysplastica

2017 ◽  
Vol 60 (12) ◽  
pp. 635-638 ◽  
Author(s):  
Ryojun Takeda ◽  
Masaki Takagi ◽  
Hiroyuki Shinohara ◽  
Hiroshi Futagawa ◽  
Satoshi Narumi ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Japanese Patient ◽  
Compound Heterozygous ◽  
Whole Exome ◽  
Compound Heterozygous Mutations

scholarly journals Mechanisms of Congenital Myasthenia Caused by Three Mutations in the COLQ Gene

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaona Luo ◽  
Chunmei Wang ◽  
Longlong Lin ◽  
Fang Yuan ◽  
Simei Wang ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Neuromuscular Junctions ◽  
Three Dimensional ◽  
Missense Variant ◽  
Homozygous Deletion ◽  
Dimensional Structure ◽  
Compound Heterozygous ◽  
Splicing Mutation ◽  
Gene Encoding ◽  
Congenital Myasthenia

The gene encoding collagen like tail subunit of asymmetric acetylcholinesterase (COLQ) is responsible for the transcription of three strands of collagen of acetylcholinesterase, which is attached to the endplate of neuromuscular junctions. Mutations in the COLQ gene are inherited in an autosomal-recessive manner and can lead to type V congenital myasthenia syndrome (CMS), which manifests as decreased muscle strength at birth or shortly after birth, respiratory failure, restricted eye movements, drooping of eyelids, and difficulty swallowing. Here we reported three variants within COLQ in two unrelated children with CMS. An intronic variant (c.393+1G>A) and a novel missense variant (p.Q381P) were identified as compound heterozygous in a 13-month-old boy, with the parents being carriers of each. An intragenic deletion including exons 14 and 15 was found in a homozygous state in a 12-year-old boy. We studied the relative expression of the COLQ and AChE gene in the probands' families, performed three-dimensional protein structural analysis, and analyzed the conservation of the missense mutation c.1142A>C (p.Q381P). The splicing mutation c.393+1G>A was found to affect the normal splicing of COLQ exon 5, resulting in a 27-bp deletion. The missense mutation c.1142A>C (p.Q381P) was located in a conserved position in different species. We found that homozygous deletion of COLQ exons 14–15 resulted in a 241-bp deletion, which decreased the number of amino acids and caused a frameshift translation. COLQ expression was significantly lower in the probands than in the probands' parents and siblings, while AChE expression was significantly higher. Moreover, the mutations were found to cause significant differences in the predicted three-dimensional structure of the protein. The splicing mutation c.393+1G>A, missense mutation c.1A>C (p.Q381P), and COLQ exon 14–15 deletion could cause CMS.

scholarly journals GEN-03 GENOTYPE-PHENOTYPE CORRELATION IN 111 FAMILIES OF VON HIPPEL-LINDAU DISEASE IN JAPAN

2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii8-ii8
Author(s):  
Hiroshi Kanno ◽  
Tetsuya Yoshizumi ◽  
Masamichi Shinonaga ◽  
Masahiro Yao
Keyword(s):  
Amino Acids ◽  
Missense Mutation ◽  
Splice Site ◽  
Phenotype Correlation ◽  
Exon 2 ◽  
Endolymphatic Sac Tumor ◽  
Von Hippel Lindau ◽  
Genotype Phenotype Correlation ◽  
Exon 1 ◽  
Vhl Disease

Abstract BACKGROUND AND AIM von Hippel-Lindau (VHL) disease is a hereditary disease which manifest central nervous system (CNS) hemangioblastoma, retinal angioma, renal cell carcinoma (RCC), pheochromocytoma, endolymphatic sac tumor, and pancreas cyst. The VHL gene is located at 3p25.3 and is corresponding to 213 amino acids. Genotype-phenotype correlation analyses of VHL disease have been recently reported from several foreign countries, but the genotype-phenotype correlation has not been characterized since above 10 years ago. Therefore, this study aimed to evaluate the VHL mutation spectrum and genotype-phenotype correlations in Japanese VHL patients. METHODS Blood samples of 111 unrelated families of VHL disease were collected and DNAs were extracted. Direct sequencing and real-time PCR analysis were performed. Consequently, the clinical manifestations and family histories of the subjects were evaluated. RESULTS We identified VHL mutations as follows: missense 47; deletion 17; insertion 5; nonsense 8; splice-site 9; larger deletion 25. At hot-spot codon 167, 4 minsense mutations were identified, with Arg167Trp, 4 cases; Arg167Gln2, 2 cases. At codon 155, splice-site mutations were identified at 6 cases. Mutation sites were distributed in exon 1, 45; exon 2, 21; exon 3, 36. Large deletions were distributed in exon 1 & 2, 1; exon 2& 3, 1; all exons, 11. Genotype-phenotype correlation analysis revealed that age-specific risk and number of CNS hemangioblastoma were significantly higher in subjects carrying missense mutation within HIF-α binding site or non-missense mutation (P < 0.05). In addition, penetrance of RCC was significantly higher in subjects carrying non-missense mutation (P < 0.05). CONCLUSIONS The results of this study were similar to the previous foreign studies. This study provides insight into the genotype-phenotype correlation in that amino acids substitutions in the HIF- α binding and non-sense mutations may predispose VHL patients to age-related risk and number of CNS hemangioblastoma.

scholarly journals Goitrous Congenital Hypothyroidism and Hearing Impairment Associated with Mutations in the TPO and SLC26A4/PDS Genes

2006 ◽  
Vol 91 (7) ◽  
pp. 2678-2681 ◽  
Author(s):  
Nicole Pfarr ◽  
Guntram Borck ◽  
Andrew Turk ◽  
Ulrike Napiontek ◽  
Annerose Keilmann ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Hearing Impairment ◽  
Congenital Hypothyroidism ◽  
Sensorineural Deafness ◽  
Primary Hypothyroidism ◽  
Thyroid Peroxidase ◽  
Compound Heterozygous ◽  
Sequence Variant ◽  
Organification Defect

Abstract Context: Pendred syndrome (PS) and thyroid peroxidase (TPO) deficiency are autosomal-recessive disorders that result in thyroid dyshormonogenesis. They share congenital hypothyroidism, goiter, and an iodide organification defect as common features. Whereas the hallmark of PS is sensorineural deafness, other forms of congenital hypothyroidism may also lead to hearing impairment. Therefore, a definite diagnosis may be difficult and require molecular genetic analyses. Case Report: The propositus presented at birth with primary hypothyroidism and goiter. He also had congenital bilateral moderate hearing loss, and PS was suspected. Methods: We sequenced the SLC26A4/PDS and TPO genes in the propositus and tested familial segregation of mutations in all available family members who were phenotypically normal. The functional consequences of the identified pendrin mutation (p.R776C) were studied in vitro. Results: Sequencing of the SLC26A4/PDS gene revealed a single monoallelic missense mutation in the propositus (p.R776C). This mutation, which was inherited from his unaffected mother, has previously been identified in an individual with deafness and an enlarged vestibular aqueduct. Sequencing of the TPO gene revealed compound heterozygosity for a novel nonsense mutation (p.Q235X) and a known missense mutation (p.Y453D). The mutant pendrin (p.R776C) retained its ability to transport iodide in vitro. Conclusions: These results show that the propositus carries three sequence variants in two genes: a monoallelic SLC26A4/PDS sequence variant and compound heterozygous TPO mutations. Our study illustrates that if only a single heterozygous SLC26A4/PDS mutation is found in a patient with goiter and deafness, other genetic explanations should be considered.

scholarly journals Metabolic abnormalities in G6PC3-deficient human neutrophils result in severe functional defects

2020 ◽  
Vol 4 (23) ◽  
pp. 5888-5901
Author(s):  
Christopher McKinney ◽  
Michael Ellison ◽  
Natalie J. Briones ◽  
Angelina Baroffio ◽  
John Murphy ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Bacterial Infections ◽  
Neutrophil Function ◽  
Functional Improvement ◽  
Human Neutrophils ◽  
Compound Heterozygous ◽  
Cd11b Expression ◽  
Exon 2 ◽  
Metabolic Defects ◽  
Functional Defects

Abstract Severe congenital neutropenia type 4 (SCN-4) is an autosomal recessive condition in which mutations in the G6PC3 gene encoding for the catalytic 3 subunit of glucose-6-phosphatase-β result in neutropenia, neutrophil dysfunction, and other syndromic features. We report a child with SCN-4 caused by compound heterozygous mutations in G6PC3, a previously identified missense mutation in exon 6 (c.758G>A[p.R235H]), and a novel missense mutation in exon 2 (c.325G>A[p.G109S]). The patient had recurrent bacterial infections, inflammatory bowel disease, neutropenia, and intermittent thrombocytopenia. Administration of granulocyte colony–stimulating factor (G-CSF) resolved the neutropenia and allowed for detailed evaluation of human neutrophil function. Random and directed migration by the patient’s neutrophils was severely diminished. Associated with this were defects in CD11b expression and F-actin assembly. Bactericidal activity at bacteria/neutrophil ratios >1:1 was also diminished and was associated with attenuated ingestion. Superoxide anion generation was <25% of control values, but phox proteins appeared quantitatively normal. Extensive metabolomics analysis at steady state and upon incubation with stable isotope–labeled tracers (U-13C-glucose, 13C,15N-glutamine, and U-13C-fructose) demonstrated dramatic impairments in early glycolysis (hexose phosphate levels), hexosemonophosphate shunt (required for the generation of the NADPH), and the total adenylate pool, which could explain the dramatic cell dysfunction displayed by the patient’s neutrophils. Preliminary experiments with fructose supplementation to bypass the enzyme block demonstrated that the metabolic profile could be reversed, but was not sustained long enough for functional improvement. In human deficiency of G6PC3, metabolic defects resulting from the enzyme deficiency account for diverse neutrophil functional defects and present a major risk of infection.

scholarly journals Intragenic variants in the SMN1 gene determine the clinical phenotype in 5q spinal muscular atrophy

2020 ◽  
Vol 6 (5) ◽  
pp. e505
Author(s):  
Rodrigo de Holanda Mendonça ◽  
Ciro Matsui ◽  
Graziela Jorge Polido ◽  
André Macedo Serafim Silva ◽  
Leslie Kulikowski ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Copy Number ◽  
Clinical Phenotype ◽  
Muscular Atrophy ◽  
Large Population ◽  
Survival Motor Neuron ◽  
Compound Heterozygous ◽  
Pathogenic Variants ◽  
Exon 1 ◽  
Compound Heterozygous Variants

ObjectiveThe aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number.MethodsFour hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing.ResultsFour hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies.ConclusionsPatients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.

Sign in / Sign up

Export Citation Format

Share Document