Genetic basis of hypertrophic cardiomyopathy in children
CLINICAL RESEARCH IN CARDIOLOGY
Authors: Rupp, Stefan; Felimban, Moataz; Schaenzer, Anne; Schranz, Dietmar; Marschall, Christoph; Zenker, Martin; Logeswaran, Thushiha; Neuhaeuser, Christoph; Thul, Josef; Jux, Christian; Hahn, Andreas
Abstract
BackgroundPrevious investigations assessing the genetic cause of pediatric hypertrophic cardiomyopathy (HCM) found underlying genetic mutations in 50-60% of cases. The purpose of our study was to analyze whether this number can be augmented by applying next-generation sequencing and directing further diagnostics by discussing unsolved cases in a multidisciplinary board.Methods and results42 patients with the diagnoses of HCM made before age 18years were treated in our center from 2000 to 2016. Genetic analysis was performed in 36 subjects, a genetic defect was detected in 29 (78%) patients. 15 individuals (42%) had pathogenic variants in genes encoding sarcomere proteins, and 5 (14%) in genes coding for components of the RAS/MAPK signaling pathway. 4 subjects (11%) had mutations in the GAA gene (Pompe disease), and 3 (8%) had Frataxin repeat expansions (Friedreich's ataxia). One patient each showed a mutation in BAG3 and LMNA. Discussion of unsolved HCM cases after performing next-generation sequencing (28 genes) in an interdisciplinary board unraveled the genetic cause in 9 subjects (25%).ConclusionA definite genetic diagnosis can be reached in nearly 80% with HCM of childhood onset. Next-generation sequencing in conjunction with a multidisciplinary cooperation can enhance the diagnostic yield substantially. This may be important for risk stratification, treatment planning and genetic counseling.
Case reports of a c.475G > T, p.E159*lamin A/C mutation with a family history of conduction disorder, dilated cardiomyopathy and sudden cardiac death
BMC CARDIOVASCULAR DISORDERS
Authors: Yokokawa, Tetsuro; Ichimura, Shohei; Hijioka, Naoko; Kaneshiro, Takashi; Yoshihisa, Akiomi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Ishida, Takafumi; Suzuki, Osamu; Ohno, Seiko; Aiba, Takeshi; Ohtani, Hiroshi; Takeishi, Yasuchika
Abstract
Background: Patients with some mutations in the lamin A/C (LMNA) gene are characterized by the presence of dilated cardiomyopathy (DCM), conduction abnormalities, ventricular tachyarrhythmias (VT), and sudden cardiac death (SCD). Various clinical features have been observed among patients who have the same LMNA mutation. Here, we show a family with cardiac laminopathy with a c.475G > T, p.E159* LMNA mutation, and a family history of conduction disorder, DCM, VT, and SCD. Case presentation: A proband (female) with atrial fibrillation and bradycardia was implanted with a pacemaker in her fifties. Twenty years later, she experienced a loss of consciousness due to polymorphic VT. She had a serious family history; her mother and elder sister died suddenly in their fifties and sixties, respectively, and her nephew and son were diagnosed as having DCM. Genetic screening of the proband, her son, and nephew identified a nonsense mutation (c.475G > T, p.E159*) in the LMNA gene. Although the proband's left ventricular ejection fraction remained relatively preserved, her son and nephew's left ventricular ejection fraction were reduced, resulting in cardiac resynchronization therapy by implantation of a defibrillator. Conclusions: In this family with cardiac laminopathy with a c.475G > T, p.E159* LMNA mutation, DCM, SCD, and malignant VT occurred. Clinical manifestation of various atrial and ventricular arrhythmias and heart failure with reduced ejection fraction occurred in an age-dependent manner in all family members who had the nonsense mutation. It appears highly likely that the E159* LMNA mutation is related to various cardiac problems in the family of the current report.