Genetic analysis using targeted next-generation sequencing of sporadic Chinese patients with idiopathic dilated cardiomyopathy.
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ABSTRACT: Background
Inherited dilated cardiomyopathy (DCM) contributes to approximately 25% of idiopathic DCM cases, and the proportion is even higher in familial DCM patients. Most studies have focused on familial DCM, whereas the genetic profile of sporadic DCM in Chinese patients remains unknown.Methods
Between June 2018 and September 2019, 24 patients diagnosed with idiopathic DCM without a family history were included in the present study. All patients underwent genetic screening for 80 DCM-related genes using targeted next-generation sequencing.Results
By in silico analysis, 10 of 99 detected variants were considered pathogenic or likely-pathogenic, including seven TTN truncating variants (TTNtv), one in-frame deletion in TNNT2, one missense mutation in RBM20, and one frameshift deletion variant in FLNC. Of these variants, eight are reported for the first time.Conclusions
Using targeted next-generation sequencing, potential genetic causes of idiopathic DCM were identified. Sarcomere mutations remained the most common genetic cause of inherited DCM in this cohort of sporadic Chinese DCM.
SUBMITTER: Li M
PROVIDER: S-EPMC8091742 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundSudden cardiac death (SCD) risk stratification in dilated cardiomyopathy (DCM) has been based on left ventricular ejection fraction (LVEF), even though SCD may occur with LVEF > 35%. Family history of unexplained SCD, especially in the young, raises concern about potential inheritable risk factors. It remains largely unknown how genetic tests can be integrated into clinical practice, particularly in the selection of implantable cardioverter defibrillator (ICD) candidates. We aimed to assess the diagnostic yield of genetic testing in DCM patients with a class I recommendation for ICD implantation, based on current guidelines.MethodsWe included ambulatory stable adult patients with idiopathic or familial DCM with previously implanted ICD. Molecular analysis included 15 genes (LMNA, MYH7, MYBPC3, TNNT2, ACTC1, TPM1, CSRP3, TCAP, SGCD, PLN, MYL2, MYL3, TNNI3, TAZ, and LDB3) using next-generation sequencing.ResultsWe evaluated 21 patients, 12 (57%) males and 9 (43%) with familial DCM, including 3 (14%) with a family history of premature unexplained SCD. Mean age at DCM diagnosis was 40 ± 2 years, and mean age at ICD implantation was 50 ± 12 years. LVEF was 27 ± 9%, and LV end-diastolic diameter was 65 ± 7 mm. Genetic variants were found in six (29%) patients, occurring in 5 genes: TPM1, TNNT2, MYH7, PLN, and MYBPC3. The majority were classified as variants of uncertain significance. Family history of SCD was present in both patients with PLN variants.ConclusionIn patients with DCM and ICD, genetic variants could be identified in a significant proportion of patients in several genes, highlighting the potential role of genetics in DCM SCD risk stratification.
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Project description:BackgroundIdiopathic generalized epilepsy is the most common group of epilepsy disorders in children and adolescents. Various types of genetic abnormality were identified among the hereditary factors that explain epilepsy.AimsTo determine the variations in the etiopathogenesis, treatment protocol planning, and prognosis of idiopathic generalized epilepsy using the next-generation sequencing method.Study designA cross-sectional study.MethodsThis study included 32 patients with idiopathic generalized epilepsy. Genomic DNA was obtained from peripheral venous blood samples taken from the patients. A total of 18 genes encoding ion channel subunits that are involved in monogenic disorders and are associated with idiopathic generalized epilepsy were included. The targeted custom next-generation sequencing panel was designed to cover all coding exons and all exon/intron splice site regions of 18 genes.ResultsWe detected 9 (28%) variations, including 1 likely pathogenic (a variant in the SCN1A gene) and 8 of unknown clinical significance (2 in the CLCN2 genes, GABBR2, SCN1B, SLC2A1, SLC4A10 genes, and 2 in the TBC1D24 gene).ConclusionStudy results should be supported by functional advanced studies, with increased existing knowledge in the relevant variations.
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Project description:Dilated cardiomyopathy (DCM) is one of the leading causes of heart failure. A large proportion of genetic cause remains unexplained, especially in idiopathic DCM. We performed target next-generation sequencing of 102 genes which were known causes or candidate genes for cardiomyopathies and channelpathies in 118 prospectively recruited Han Chinese patients with idiopathic DCM. 41 of the 118 patients carried 40 pathogenic or likely pathogenic variants, providing a molecular diagnosis in 34.7% of patients. 32 of these variants were novel. TTN truncating variants were predominant, with a frequency of 31.0%, followed by variants of LMNA (14.3%), RBM20 (4.8%), and NEXN (4.8%). These 4 genes accounted for over half variants identified. No significant difference in clinical characteristics or rates of reaching the composite end point (cardiac transplantation and death from cardiac causes) between pathogenic or likely pathogenic variant carriers and noncarriers (hazard ratio 1.11, 95% CI: 0.41 to 3.00), or between patients with TTN truncating variants or without (hazard ratio 0.49, 95% CI: 0.36 to 6.10). In our prospective study, we first determined the overall genetic profiles and genotype-phenotype correlations in Han Chinese idiopathic DCM patients, which could provide insight for genetic diagnosis of DCM in this population.
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