Acuña-Ochoa Jose G, Balderrábano-Saucedo Norma A, Cepeda-Nieto Ana C, Alvarado-Cervantes Maria Y, Ibarra-Garcia Vianca L, Barr Daniel, Gage Matthew J, Pfeiffer Ryan, Hu Dan, Barajas-Martinez Hector
Cardiovascular Research Department, Lankenau Institute for Medical Research, Lankenau Hearth Institute, Wynnewood, Pennsylvania 19096, USA.
Cardiomyopathies and Arrhythmias Research Laboratory/Department, Federico Gómez Children's Hospital of Mexico, Mexico 06720, Mexico.
Case Rep Genet. 2024 Dec 28;2024:9517735. doi: 10.1155/crig/9517735. eCollection 2024.
Structural or electrophysiologic cardiac anomalies may compromise cardiac function, leading to sudden cardiac death (SCD). Genetic screening of families with severe cardiomyopathies underlines the role of genetic variations in cardiac-specific genes. The present study details the clinical and genetic characterization of a malignant dilated cardiomyopathy (DCM) case in a 1-year-old Mexican child who presented a severe left ventricular dilation and dysfunction that led to SCD. A total of 132 genes (48 structure- and 84 electrical-related genes) were examined by next generation sequencing to identify potential causative mutations in comparison to control population. analysis identified only two deleterious heterozygous mutations within an evolutionarily well-conserved region of the sarcomeric genes /cardiac actin (c.664G > A/p.Ala222Thr) and /titin (c.33250G > A/p.Glu11084Lys). Further pedigree analysis revealed the father of the index case to carry with the mutation. Surprisingly, the mutation was not harbored by any first-degree family member. Computational 3D modeling of the mutated proteins showed electrostatic and conformational shifts of cardiac actin compared to wild-type version, as well as changes in the stability of the compact/folded states of titin that normally contributes to avoid mechanic damage. In conclusion, our findings suggest a likely pathogenic mutation in in coexpression of a variant as possible causes of an early onset of a severe DCM and premature death. These results may increase the known clinical pathogenic variations that may critically alter the structure of the heart, whose fatality could be prevented when rapidly detected.
结构性或电生理心脏异常可能损害心脏功能,导致心源性猝死(SCD)。对患有严重心肌病的家族进行基因筛查突显了心脏特异性基因中基因变异的作用。本研究详细描述了一名1岁墨西哥儿童的恶性扩张型心肌病(DCM)病例的临床和基因特征,该患儿出现严重左心室扩张和功能障碍,最终导致SCD。通过下一代测序检查了总共132个基因(48个结构相关基因和84个电相关基因),以与对照人群比较识别潜在的致病突变。分析仅在肌节基因心脏肌动蛋白(c.664G>A/p.Ala222Thr)和肌联蛋白(c.33250G>A/p.Glu11084Lys)进化上高度保守区域内发现两个有害的杂合突变。进一步的家系分析显示索引病例的父亲携带该突变。令人惊讶的是,任何一级家庭成员均未携带该突变。与野生型相比,突变蛋白的计算3D模型显示心脏肌动蛋白的静电和构象变化,以及通常有助于避免机械损伤的肌联蛋白紧密/折叠状态稳定性的变化。总之,我们的研究结果表明,心脏肌动蛋白中的一个可能致病突变与肌联蛋白变体的共表达可能是严重DCM早期发作和过早死亡的原因。这些结果可能增加已知的临床致病变异,这些变异可能严重改变心脏结构,若能快速检测到则可预防其致命性。