Abstract 468: Previously Unrecognized Intronic Variants in the Dystrophin Gene Identified as Possible Contributors to Dilated Cardiomyopathy

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Alex Gyftopoulos ◽  
Tamara Ashvetiya ◽  
Yi-Ju Chen ◽  
Libin Wang ◽  
Charles H Williams ◽  
...  
Keyword(s):  
Heart Failure ◽  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
Allele Frequency ◽  
Minor Allele Frequency ◽  
Mixed Model ◽  
Dystrophin Gene ◽  
Becker Muscular Dystrophy ◽  
Minor Allele ◽  
Intronic Variants

Nonischemic dilated cardiomyopathy (DCM) often has a genetic etiology, however, its prevalence and etiologies are not completely understood. The UK Biobank comprises clinical and genetic data for greater than 500,000 individuals with enrollees 40-69 years of age. Our group created a custom phenotype of heart failure using ICD-10 codes for several subtypes of heart failure diagnoses including DCM. We then compared the individuals included in the custom heart failure phenotype to control individuals in a 20-to-1 fashion to identify genetic differences. Data were compared using Mixed Model Analysis for Pedigrees/Populations (MMAP) mixed-model regression. We identified 8 unlinked intronic variants in the dystrophin gene ( DMD ) that, when separated by self-identified race, occurred with a combined minor allele frequency of 0.15 in individuals with heart failure who identified as being of African descent. The combined minor allele frequency of these variants was 0.05 in individuals who self-identified as being of European descent. One variant of DMD in particular (rs139029250), was identified with a minor allele frequency of 0.05 in African British with DCM. The unadjusted odds ratio of a diagnosis of heart failure in individuals with rs129029250 was 4.65. When separated by gender, the unadjusted odds ratios are 2.02 for females and 6.44 for males. DMD is most notably known for its role in Duchenne and Becker muscular dystrophy, both of which are known to cause dilated cardiomyopathy in affected individuals. However, none of the individuals (36 female and 43 male) identified in our analysis with rs129029250 have been diagnosed with Duchenne muscular dystrophy, Becker muscular dystrophy, or a primary disorder of muscle (ICD code G70). Additionally, these individuals have an intronic variant of DMD , while Duchene and Becker muscular dystrophy are both due to exonic mutations. These findings suggest a possible common variant in the DMD gene that may contribute to DCM in individuals of African descent.

The heart in neuromuscular disease: Duchenne and limb girdle muscular dystrophies

ESC CardioMed ◽  
2018 ◽  
pp. 1535-1540
Author(s):  
Karim Wahbi
Keyword(s):  
Heart Failure ◽  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
Systolic Dysfunction ◽  
Genetic Diagnosis ◽  
Dystrophin Gene ◽  
Left Ventricular ◽  
Muscular Dystrophies ◽  
Circulatory Support ◽  
Converting Enzyme Inhibitors

Duchenne muscular dystrophy (DMD), the most common muscular disease, is caused by out-of-frame mutations in the dystrophin gene. Dilated cardiomyopathy is the most frequent cardiac presentation of the disease, with a prevalence increasing with age—it is uncommon before the age of 10 years and present in up to 80% after 18 years. Heart failure represents nowadays the leading cause of death in DMD. Electrocardiography and echocardiography are recommended at diagnosis and then every 2 years until 10 years of age and yearly after. Angiotensin-converting enzyme inhibitors are widely prescribed before left ventricular dysfunction is detected, generally before 10 years of age, with an indication supported by the results of a randomized trial showing a benefit in terms of prevention of systolic dysfunction and survival. Beta-adrenergic blockers and eplerenone are also promising medications for this indication, but additional studies are warranted to determine their benefit. Glucocorticoids, which are currently recommended in patients with DMD who are 5 years of age or older to protect muscular and pulmonary function, could also improve left ventricular function and long-term cardiac prognosis. An implantable cardioverter defibrillator and mechanical circulatory support can be indicated in selected patients. The term limb girdle muscular dystrophy encompasses a heterogeneous group of muscular dystrophies involving more than 30 genes and various prevalence and severity of cardiac disease, mostly dilated cardiomyopathy. Electrocardiography and echocardiography are recommended at diagnosis and thereafter according to initial findings and genetic diagnosis. Heart failure management should follow the same criteria as for the other forms of dilated cardiomyopathy.

Effect of Ivabradine in dilated cardiomyopathy from Duchenne muscular dystrophy: A chance for slowing progression of heart failure?

2016 ◽  
Vol 223 ◽  
pp. 286-288 ◽  
Author(s):  
Giuseppina De Benedittis ◽  
Giulia Della Rosa ◽  
Enzo D'Ettorre ◽  
Prisco Piscitelli ◽  
Alessandro Distante ◽  
...  
Keyword(s):  
Heart Failure ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy

P–541 Identification of novel variants and candidate genes in women with familial idiopathic premature ovarian failure using whole-exome sequencing

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
R Morale. Sabater ◽  
B Lledo ◽  
J A Ortiz ◽  
F Lozano ◽  
A Bernabeu ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Candidate Genes ◽  
Allele Frequency ◽  
Whole Exome Sequencing ◽  
Minor Allele Frequency ◽  
Premature Ovarian Failure ◽  
Ovarian Function ◽  
Ovarian Failure ◽  
Minor Allele ◽  
Whole Exome

Abstract Study question Is it possible to identify a genetic cause of familial premature ovarian failure (POF) with whole-exome sequencing (WES)? Summary answer Whole-exome sequencing is the most efficient strategy to identify probably pathogenic mutations in different genes in pathologies of polygenic etiology such as premature ovarian failure. What is known already Premature ovarian failure is the loss of ovarian function before the age of 40, and it is a common cause of infertility in women. This pathology has a heterogeneous etiology. Some chromosomal and genetic alterations have been described, and could explain approximately 20% of cases. However, in most patients the origin remains unknown. Recent studies with next-generation sequencing (NGS) have identified new variants in candidate genes related with premature ovarian insufficiency (POI) or premature ovarian failure (POF). These genes are not only involved in processes such as folliculogenesis, but also with DNA damage repair, homologous recombination, and meiosis. Study design, size, duration Fourteen women, from 7 families, affected by idiopathic POF were included in the study from October 2019 to September 2020. Seven POF patients were recruited when they came to our clinic to undergo assisted reproductive treatment. In the anamnesis, it was found that they had relatives with a diagnosis of POF, who were also recruited for the study. The inclusion criteria were amenorrhea before 38 years old and analytical and ultrasound signs of ovarian failure. Participants/materials, setting, methods WES was performed using TrusightOne (Illumina®). Sequenced data were aligned through BWA tool and GATK algorithm was used for SNVs/InDel identification. VCF files were annotated using Variant Interpreter software. Only the variants shared by each family were extracted for analysis and these criteria were followed: (1) Exonic/splicing variants in genes related with POF or involved in biological ovarian functions (2) Variants with minor allele frequency (MAF) ≤0.05 and (3) having potentially moderate/strong functional effects. Main results and the role of chance Seventy-nine variants possibly related with the POF phenotype were identified in the seven families. All these variants had a minor allele frequency (MAF) ≤0.05 in the gnomAD database and 1000 genomes project. Among these candidate variants, two were nonsense, six splice region, one frameshift, two inframe deletion and 68 missense. Thirty-two of the missense variants were predicted to have deleterious effects by minimum two of the four in silico algorithms used (SIFT, PolyPhen–2, MutationTaster and PROVEAN). All variants were heterozygous, and all the families carried three or more candidate variants. Altogether, 43 probably damaging genetic variants were identified in 39 genes expressed in the ovary and related with POF/POI or linked to ovarian physiology. We have described genes that have never been associated to POF pathology, however they may be involved in key biological processes for ovarian function. Moreover, some of these genes were found in two families, for example DDX11, VWF, PIWIL3 and HSD3B1. DDX11 may function at the interface of replication-coupled DNA repair and sister chromatid cohesion. VWF gene is suggested to be associated with follicular atresia in previous studies. PIWIL3 functions in development and maintenance of germline stem cells, and HSD3B1 is implicated in ovarian steroidogenesis. Limitations, reasons for caution Whole-exome sequencing has some limitations: does not cover noncoding regions of the genome, it also cannot detect large rearrangements, copy-number variants (large deletions/duplications), mosaic mutations, mutations in repetitive or high GC rich regions and mutations in genes with corresponding pseudogenes or other highly homologous sequences. Wider implications of the findings: WES has previously shown to be an efficient tool to identify genes as cause of POF, and has demonstrated the polygenic etiology. Although some studies have focused on it, and many genes are identified, this study proposes new candidate genes and variants, having potentially moderate/strong functional effects, associated with POF. Trial registration number Not applicable

MO275RARE VARIANTS OF COMPLEMENT FACTOR H AND THROMBOMODULIN ARE OVER-REPRESENTED IN A COHORT OF SEVERE IGA NEPHROPATHY PATIENTS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Nicolas Maillard ◽  
Veronique Fremeaux Bacchi ◽  
Paula Vieira-Martins ◽  
Perrine Jullien ◽  
Eric Alamartine ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Allele Frequency ◽  
Rare Variant ◽  
Minor Allele Frequency ◽  
Rare Variants ◽  
Regulatory Genes ◽  
Factor H ◽  
Minor Allele ◽  
Risk Haplotype ◽  
Complement Factor

Abstract Background and Aims IgA nephropathy is the most frequent primary glomerulonephritis leading to end stage renal disease (ESRD) in about 30% of cases within 20 years after diagnosis. Complement activation through alternative and lectin pathways has been described to impact the pathogeny of the disease. We hypothesized in this study that rare variants of alternative pathways regulatory genes could be overrepresented and could play a role at initiating the disease and could harm the prognosis of IgA Nephropathy. Method Patients with biopsy proven IgA nephropathy with markers of severity comprising an evolution through ESRD and/or a proteinuria >0.5g/day with available DNA sample were included. All coding sequences of CFH, CFI, MCP, C3, Factor B THBD and CFHR5 genes were analyzed by next generation sequencing. We defined a variant as rare when its minor allele frequency was below 0.1% in the general population. Frequencies were compared to a French volonteers cohort (n=80) and a European large cohort (n=503) Results We screened 128 patients with IgA N, with following characteristics at diagnosis: median age 42.4 yo, proteinuria (median) 1.4g/day, hypertension 66%, median eGFR 48.7 mL/min/1.73m². The median follow-up was 99 months and 58% of patients progressed to ESRD. We identified rare variants with MAF<0.1% in 10.2 % (n=13) including 1 patient with two rare variants. The functional consequences of the 12 out the 14 variants are unknown. Two variants in CFH are located in function domains and are pathogenic. Patients with IgA N have high rates of rare variants in CFH (n=9/128 ; 7 %) versus normal controls (n=9/503 ; 1.8%) (p=0.004); Pathogenic Variants with minor allele frequency <0.1% in CFH were found in 2 IgA N (2 out of 128, 1.5%) versus 1 European controls (1 out of 503) In total, 11 % (14/128), 3.8 % (5/128) and 0.8 % (1/128) of the 128 patients were homozygous for the at-risk haplotype MCP ggaac, CFH tgtgt or both, respectively (versus 6.2 % (5/80), 3.8 % (3/80) and 0% in the controls) 6 patients carried the pathogenic variant in THDM gene p.Ala43Thr (6/128) versus 5 in 508 controls population (p=0.01). No difference in term of hypertension, proteinuria, eGFR, Oxford classification, vascular score at diagnosis was noticed between patients without any rare variant compared to patients with at least one rare variant. The progression through ESRD was not different between groups. Conclusion In this cohort of Caucasian IgA nephropathy patients, rare variants of CFH and THBD were found significantly overrepresented compared to a French and European control cohort. Rare variants of alternative pathway regulatory genes were not associated with particular severity or prognosis.

Congestive Heart Failure With Rhabdomyolysis and Acute Renal Failure in a Manifesting Female Carrier of Duchenne Muscular Dystrophy With Duplication of Dystrophin Gene

2009 ◽  
Vol 11 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Atchara Tunteeratum ◽  
Rawiphan Witoonpanich ◽  
Suchart Phudhichareonrat ◽  
Jakris Eu-ahsunthornwattana ◽  
Sarinee Pingsuthiwong ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Renal Failure ◽  
Acute Renal Failure ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Dystrophin Gene ◽  
Female Carrier

Mutation profile of over 4500 SARS-CoV-2 isolations reveals prevalent cytosine-to-uridine deamination on viral RNAs

2020 ◽  
Vol 15 (14) ◽  
pp. 1343-1352
Author(s):  
Yue Li ◽  
Xinai Yang ◽  
Na Wang ◽  
Haiyan Wang ◽  
Bin Yin ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Point Mutation ◽  
Minor Allele Frequency ◽  
Point Mutations ◽  
Minor Allele ◽  
Unique Point ◽  
Random Mutation ◽  
Viral Rnas ◽  
Mutation Profile ◽  
Mutation Type

Aim: The inference of coronavirus evolution is largely based on mutations in SARS-CoV-2 genome. Misinterpretation of these mutations would mislead people about the evolution of SARS-CoV-2. Materials & methods: With 4521 lines of SARS-CoV-2, we obtained 3169 unique point mutation sites. We counted the numbers and calculated the minor allele frequency (MAF) of each mutation type. Results: Nearly half of the point mutations are C–T mismatches and 20% are A–G mismatches. The MAF of C–T and A–G mismatches is significantly higher than MAF of other mutation types. Conclusion: The excessive C–T mismatches do not resemble the random mutation profile. They are likely to be caused by the cytosine-to-uridine deamination system in hosts.

Proportion and pattern of dystrophin gene deletions in North Indian Duchenne and Becker muscular dystrophy patients

1997 ◽  
Vol 99 (2) ◽  
pp. 206-208 ◽  
Author(s):  
Vinita Singh ◽  
Shirish Sinha ◽  
Sudhish Mishra ◽  
Lakshmi Shankar Chaturvedi ◽  
Sunil Pradhan ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Dystrophin Gene ◽  
Becker Muscular Dystrophy ◽  
Gene Deletions
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