scholarly journals ABCC6 Gene Analysis in 20 Japanese Patients with Angioid Streaks Revealing Four Frequent and Two Novel Variants and Pseudodominant Inheritance

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Satoshi Katagiri ◽  
Yuya Negishi ◽  
Kei Mizobuchi ◽  
Mitsuyoshi Urashima ◽  
Tadashi Nakano ◽  
...  
Keyword(s):  
Medical Records ◽  
Sanger Sequencing ◽  
Pseudoxanthoma Elasticum ◽  
Japanese Patients ◽  
Compound Heterozygous ◽  
Angioid Streaks ◽  
Dermatological Examination ◽  
Abcc6 Gene ◽  
Novel Variants ◽  
Unknown Significance

Purpose. To report the spectrum of ABCC6 variants in Japanese patients with angioid streaks (AS). Patients and Methods. This was a single-center cohort study. The medical records of 20 patients with AS from 18 unrelated Japanese families were retrospectively reviewed. Screening of the ABCC6 gene (exons 1 to 31) was performed using PCR-based Sanger sequencing. Results. Eight ABCC6 variants were identified as candidate disease-causing variants. These eight variants included five known variants (p.Q378X, p.R419Q, p.V848CfsX83, p.R1114C, and p.R1357W), one previously reported variant (p.N428S) of unknown significance, and two novel variants (c.1939C>T [p.H647Y] and c.3374C>T [p.S1125F]); the three latter variants were determined to be variants of significance. The following four variants were frequently identified: p.V848CfsX83 (14/40 alleles, 35.0%), p.Q378X (7/40 alleles, 17.5%), p.R1357W (6/40 alleles, 15.0%), and p.R419Q (4/40 alleles, 10.0%). The ABCC6 variants were identified in compound heterozygous or homozygous states in 13 of 18 probands. Two families showed a pseudodominant inheritance pattern. Pseudoxanthoma elasticum was seen in 15 of 17 patients (88.2%) who underwent dermatological examination. Conclusions. We identified disease-causing ABCC6 variants that were in homozygous or compound heterozygous states in 13 of 18 families (72.2%). Our results indicated that ABCC6 variants play a significant role in patients with AS in the Japanese population.

scholarly journals Novel variants in DNAH9 lead to nonsyndromic severe asthenozoospermia

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dongdong Tang ◽  
Yanwei Sha ◽  
Yang Gao ◽  
Jingjing Zhang ◽  
Huiru Cheng ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Sperm Morphology ◽  
Immunofluorescence Staining ◽  
Compound Heterozygous ◽  
Sperm Tail ◽  
Transmission Electron ◽  
Whole Exome ◽  
Detailed Medical History ◽  
Novel Variants ◽  
Common Causes

Abstract Background Asthenozoospermia is one of the most common causes of male infertility, and its genetic etiology is poorly understood. DNAH9 is a core component of outer dynein arms in cilia and flagellum. It was reported that variants of DNAH9 (OMIM: 603330) might cause primary ciliary dyskinesia (PCD). However, variants in DNAH9 lead to nonsyndromic severe asthenozoospermia have yet to be reported. Methods Whole exome sequencing (WES) was performed for two individuals with nonsyndromic severe asthenozoospermia from two non-consanguineous families, and Sanger sequencing was performed to verify the identified variants and parental origins. Sperm routine analysis, sperm vitality rate and sperm morphology analysis were performed according the WHO guidelines 2010 (5th edition). Transmission electron microscopy (TEM, TECNAI-10, 80 kV, Philips, Holland) was used to observe ultrastructures of sperm tail. Quantitative realtime-PCR and immunofluorescence staining were performed to detect the expression of DNAH9-mRNA and location of DNAH9-protein. Furthermore, assisted reproductive procedures were applied. Results By WES and Sanger sequencing, compound heterozygous DNAH9 (NM_001372.4) variants were identified in the two individuals with nonsyndromic severe asthenozoospermia (F1 II-1: c.302dupT, p.Leu101fs*47 / c.6956A > G, p.Asp2319Gly; F2 II-1: c.6294 T > A, p.Phe2098Leu / c.10571 T > A, p.Leu3524Gln). Progressive rates less than 1% with normal sperm morphology rates and normal vitality rates were found in both of the two subjects. No respiratory phenotypes, situs inversus or other malformations were found by detailed medical history, physical examination and lung CT scans etc. Moreover, the expression of DNAH9-mRNA was significantly decreased in sperm from F1 II-1. And expression of DNAH9 is lower in sperm tail by immunofluorescence staining in F1 II-1 compared with normal control. Notably, by intracytoplasmic sperm injection (ICSI), F1 II-1 and his partner successfully achieved clinical pregnancy. Conclusions We identified DNAH9 as a novel pathogenic gene for nonsyndromic severe asthenospermia, and ICSI can contribute to favorable pregnancy outcomes for these patients.

Novel mutations of ABCC6 gene in Japanese patients with Angioid streaks

2009 ◽  
Vol 380 (3) ◽  
pp. 548-553 ◽  
Author(s):  
Naoyuki Sato ◽  
Tomohiro Nakayama ◽  
Yoshihiro Mizutani ◽  
Mitsuko Yuzawa
Keyword(s):  
Japanese Patients ◽  
Angioid Streaks ◽  
Novel Mutations ◽  
Abcc6 Gene

Identification of ABCC6 gene mutations in the Japanese patients with pseudoxanthoma elasticum (PXE)

2013 ◽  
Vol 69 (2) ◽  
pp. e57-e58
Author(s):  
Akira Iwanaga ◽  
Mariko Yozaki ◽  
Yosuke Yagi ◽  
Koji Maemura ◽  
Eiko Tsuiki ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Pseudoxanthoma Elasticum ◽  
Japanese Patients ◽  
Abcc6 Gene

scholarly journals Seven novel genetic variants in a North Indian cohort with classical homocystinuria

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rajdeep Kaur ◽  
Savita V. Attri ◽  
Arushi G. Saini ◽  
Naveen Sankhyan ◽  
Satwinder Singh ◽  
...  
Keyword(s):  
Family History ◽  
Sanger Sequencing ◽  
Catalytic Domain ◽  
Positive Family History ◽  
Compound Heterozygous ◽  
Indian Children ◽  
Pathogenic Variants ◽  
Novel Variants ◽  
Frequent Mutations ◽  
Novel Therapeutic Strategies

Abstract Classical homocystinuria is the most common cause of isolated homocystinuria. The variants of the CBS gene remain unidentified in Indian children with this disorder. Based on the hallmark clinical features, family history, and/or biochemical clues for classical homocystinuria, 16 children below the age of 18 years were evaluated by Sanger sequencing of the coding exons of CBS gene with flanking intronic regions. The common C677T variant of the MTHFR gene was also screened by restriction fragment length polymorphism. Fifteen children were clinically suspected of having classical homocystinuria and one asymptomatic child with positive family history. Only seven children had biochemical features of classical homocystinuria. Sanger sequencing of the CBS gene confirmed 15 different pathogenic or likely pathogenic variants in 14 cases. Of these, seven variants were novel (three frameshift deletions, two nonsense, one missense, one splice site variant) and were predicted to be deleterious by Mutation Taster software. Seven cases were homozygous, another six were compound heterozygous, and one case was single heterozygous in the study. None of the three most frequent mutations reported worldwide viz., I278T, G307S, and IVS 11-2A>C were found in our cohort. No variants were detected in the exons 2, 8, 12, and 14 as compared to reported literature. Eleven out of 15 variants were associated with the conserved catalytic domain of the CBS polypeptide. The MTHFR polymorphism C677T was observed in heterozygous state in six cases. Our study reports the detailed genotype and seven novel variants in the CBS gene, causing classical homocystinuria in Indian children. The genetic analysis will help to offer accurate genetic counseling, prenatal diagnosis, and development of mutation-based novel therapeutic strategies.

scholarly journals Clinical Characterization of Korean Patients with Pseudoxanthoma Elasticum and Angioid Streaks

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1207
Author(s):  
Ki Won Jin ◽  
Kwangsic Joo ◽  
Se Joon Woo
Keyword(s):  
Visual Acuity ◽  
Pseudoxanthoma Elasticum ◽  
Compound Heterozygous ◽  
Angioid Streaks ◽  
Korean Patients ◽  
Asymptomatic Patients ◽  
Ophthalmic Imaging ◽  
Novel Variant ◽  
Compound Heterozygous Variants

This study aimed to characterize Korean patients with pseudoxanthoma elasticum (PXE) presenting with angioid streaks. Retinal phenotypes were longitudinally evaluated by multimodal ophthalmic imaging, and targeted gene panel sequencing for inherited retinal diseases was conducted. Seven subjects from unrelated families (median age, 51.2 years) were enrolled and followed for a median of 3.2 years. Four asymptomatic patients were significantly younger than three symptomatic patients with decreased visual acuity at presentation (mean age; 38.1 vs. 61.5 years, p = 0.020). The asymptomatic patients maintained good vision (20/32 or better) and had no choroidal neovascularization (CNV) over the observation period. The symptomatic patients showed additional reduction in visual acuity and bilateral CNV occurrence during the longitudinal follow-up. Pathogenic ABCC6 variants were identified in all patients, leading to a diagnosis of PXE. Heterozygous monoallelic variants were identified in four patients and compound heterozygous variants were detected in three patients. Nine ABCC6 variants were identified, including one novel variant, c.2035G>T [p.Glu679Ter]. This is the first genetic study of Korean patients with PXE.

scholarly journals Novel ABCA4 mutation leads to loss of a conserved C-terminal motif: implications for predicting pathogenicity based on genetic testing

2018 ◽  
Vol 28 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Nutsuchar Wangtiraumnuay ◽  
Jenina Capasso ◽  
Mai Tsukikawa ◽  
Alex Levin ◽  
Esther Biswas-Fiss
Keyword(s):  
Amino Acids ◽  
Genetic Testing ◽  
Protein Structure ◽  
Protein Function ◽  
Macular Dystrophy ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
Variants Of Unknown Significance ◽  
Novel Variants ◽  
Unknown Significance

Purpose: Mutations in the ABCA4 gene result in a broad spectrum of severe retinal degeneration, including Stargardt macular dystrophy, fundus flavimaculatus, autosomal recessive retinitis pigmentosa, and cone-rod dystrophy. In addition to the detection of well-characterized mutations, genetic testing frequently yields novel variants of unknown significance. The purpose of this report is to describe an approach to aid in the assessment of genetic variants of unknown significance. Case report: We report an 11-year-old girl with Stargardt disease harboring novel compound heterozygous deletions of ABCA4 (c.850_857delATTCAAGA and c.6184_6187delGTCT). The pathogenicity of these variants was otherwise unknown. Both deletions introduce premature stop codons and are localized within the open reading frame of ABCA4. The c.850_857delATTCAAGA occurs early in the gene and leads to a significantly truncated protein of only 317 amino acids. The c.6184_6187delGTCT, is localized to the 3’ terminus of the ORF and results in removal of the last 161 out of 2,273 amino acids of ABCA4, including the VFVNFA motif, which has been shown to be critical in ABCA4 protein function. Homology-based protein modeling of ABCA4 harboring this deletion suggests significant alterations in the protein structure and function. Conclusions: Our analyses allowed us to classify novel variants in ABCA4 as being clearly loss-of-function mutations, and thus pathogenic variants. In cases of variants of unknown significance, appraising the protein structure-function consequences of genetic mutations using in silico tools may help to predict the clinical importance of variants of uncertain pathogenicity.

scholarly journals Novel Variants in DNAH9 Lead to Nonsyndromic Severe Asthenozoospermia

2021 ◽  
Author(s):  
Dongdong Tang ◽  
Yanwei Sha ◽  
Yang Gao ◽  
Jingjing Zhang ◽  
Huiru Cheng ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Sperm Morphology ◽  
Immunofluorescence Staining ◽  
Compound Heterozygous ◽  
Sperm Tail ◽  
Transmission Electron ◽  
Whole Exome ◽  
Detailed Medical History ◽  
Novel Variants ◽  
Common Causes

Abstract Background Asthenozoospermia is one of the most common causes of male infertility, and its genetic etiology is poorly understood. DNAH9 is a core component of outer dynein arms in cilia and flagellum. It was reported that variants of DNAH9 (OMIM: 603330) might cause primary ciliary dyskinesia (PCD). However, variants in DNAH9 lead to nonsyndromic severe asthenozoospermia have yet to be reported.Methods Whole exome sequencing (WES) was performed for two individuals with nonsyndromic severe asthenozoospermia from two non-consanguineous families, and Sanger sequencing was performed to verify the identified variants and parental origins. Sperm routine analysis, sperm vitality rate and sperm morphology analysis were performed according the WHO guidelines 2010 (5th edition). Transmission electron microscopy (TEM, TECNAI-10, 80 kV, Philips, Holland) was used to observe ultrastructures of sperm tail. Quantitative realtime-PCR and immunofluorescence staining were performed to detect the expression of DNAH9-mRNA and location of DNAH9-protein. Furthermore, assisted reproductive procedures were applied.Results By WES and Sanger sequencing, compound heterozygous DNAH9 (NM_001372.4) variants were identified in the two individuals with nonsyndromic severe asthenozoospermia (F1 II-1: c.302dupT, p.Leu101fs*47 / c.6956A>G, p.Asp2319Gly; F2 II-1: c.6294T>A, p.Phe2098Leu / c.10571T>A, p.Leu3524Gln). Progressive rates less than 1% with normal sperm morphology rates and normal vitality rates were found in both of the two subjects. No respiratory phenotypes, situs inversus or other malformations were found by detailed medical history, physical examination and lung CT scans etc. Moreover, the expression of DNAH9-mRNA was significantly decreased in sperm from F1 II-1. And expression of DNAH9 is lower in sperm tail by immunofluorescence staining in F1 II-1 compared with normal control. Notably, by intracytoplasmic sperm injection (ICSI), F1 II-1 and his partner successfully achieved clinical pregnancy. Conclusions We identified DNAH9 as a novel pathogenic gene for nonsyndromic severe asthenospermia, and ICSI can contribute to favorable pregnancy outcomes for these patients.

scholarly journals Novel ARG1 variants identified in a patient with arginase 1 deficiency

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Katsuyuki Yokoi ◽  
Yoko Nakajima ◽  
Toshihiro Yasui ◽  
Makoto Yoshino ◽  
Tetsushi Yoshikawa ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Arginase Activity ◽  
Compound Heterozygous ◽  
Measurement Sensitivity ◽  
Protein Core ◽  
Arginase 1 ◽  
Conserved Domain ◽  
New Variant ◽  
Compound Heterozygous Variants

AbstractWe report a case of a 13-year-old boy with arginase 1 deficiency carrying a new variant in ARG1. Sanger sequencing identified the compound heterozygous variants: NM_000045.4: c.365G>A (p.Trp122*)/c.820G>A (p.Asp274Asn). Although not previously reported, the p.Asp274Asn variant is predicted to have strong pathogenicity because it is located in a highly conserved domain in the protein core and arginase activity in the patient was below measurement sensitivity.

scholarly journals Genotype-Phenotype Correlations in RP1-Associated Retinal Dystrophies: A Multi-Center Cohort Study in JAPAN

2021 ◽  
Vol 10 (11) ◽  
pp. 2265
Author(s):  
Kei Mizobuchi ◽  
Takaaki Hayashi ◽  
Noriko Oishi ◽  
Daiki Kubota ◽  
Shuhei Kameya ◽  
...  
Keyword(s):  
Age At Onset ◽  
Japanese Patients ◽  
Clinical Findings ◽  
Cone Dystrophy ◽  
Element Insertion ◽  
Retinal Dystrophies ◽  
Whole Exome ◽  
Novel Variants ◽  
Alu Element ◽  
Frequent Variant

Background: Little is known about genotype–phenotype correlations of RP1-associated retinal dystrophies in the Japanese population. We aimed to investigate the genetic spectrum of RP1 variants and provide a detailed description of the clinical findings in Japanese patients. Methods: In total, 607 patients with inherited retinal diseases were examined using whole-exome/whole-genome sequencing (WES/WGS). PCR-based screening for an Alu element insertion (c.4052_4053ins328/p.Tyr1352AlafsTer9) was performed in 18 patients with autosomal-recessive (AR)-retinitis pigmentosa (RP) or AR-cone dystrophy (COD)/cone-rod dystrophy (CORD), including seven patients with heterozygous RP1 variants identified by WES/WGS analysis, and 11 early onset AR-RP patients, in whom no pathogenic variant was identified. We clinically examined 25 patients (23 families) with pathogenic RP1 variants, including five patients (five families) with autosomal-dominant (AD)-RP, 13 patients (11 families) with AR-RP, and seven patients (seven families) with AR-COD/CORD. Results: We identified 18 pathogenic RP1 variants, including seven novel variants. Interestingly, the Alu element insertion was the most frequent variant (32.0%, 16/50 alleles). The clinical findings revealed that the age at onset and disease progression occurred significantly earlier and faster in AR-RP patients compared to AD-RP or AR-COD/CORD patients. Conclusions: Our results suggest a genotype–phenotype correlation between variant types/locations and phenotypes (AD-RP, AR-RP, and AR-COD/CORD), and the Alu element insertion was the most major variant in Japanese patients with RP1-associated retinal dystrophies.

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