Divison of Cardiology, Cardiovascular Institute, University of Colorado, Aurora, Colorado, USA.
DNA Laboratory, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado, USA.
Am J Med Genet A. 2022 Feb;188(2):600-605. doi: 10.1002/ajmg.a.62530. Epub 2021 Oct 15.
Dilated cardiomyopathy (DCM) is one of the most common cardiac phenotypes caused by mutations of lamin A/C (LMNA) gene in humans. In our study, a cohort of 57 patients who underwent heart transplant for dilated cardiomyopathy was screened for variants in LMNA. We identified a synonymous variant c.936G>A in the last nucleotide of exon 5 of LMNA in a DCM family. Clinically, the LMNA variant carriers presented with severe familial DCM, conduction disease, and high creatine-kinase level. The LMNA c.936G>A variant is novel and has not been reported in current genetic variant databases. Sanger sequencing results showed the presence of LMNA c.936G>A variant in the genomic DNA but not in the cDNA derived from one family member's heart tissue. Real-time quantitative polymerase chain reaction showed significantly lower LMNA mRNA levels in the patient's heart compared to the controls, suggesting that the c.936G>A LMNA variant resulted in reduced mRNA and possibly lower protein expression of LMNA. These findings expand the understanding on the association between synonymous variant of LMNA and the molecular pathogenesis in DCM patients.
扩张型心肌病(DCM)是由人类 lamin A/C(LMNA)基因突变引起的最常见的心脏表型之一。在我们的研究中,对 57 名因扩张型心肌病接受心脏移植的患者进行了 LMNA 基因变异筛查。我们在一个 DCM 家族中发现了 LMNA 外显子 5 最后一个核苷酸的同义变异 c.936G>A。临床上,携带 LMNA 变异的患者表现为严重的家族性 DCM、传导疾病和肌酸激酶水平升高。该 LMNA c.936G>A 变异是新的,目前的遗传变异数据库中没有报道。Sanger 测序结果显示,在一个家族成员的心脏组织来源的 cDNA 中未发现 LMNA c.936G>A 变异,但在基因组 DNA 中存在。实时定量聚合酶链反应显示,与对照组相比,患者心脏中的 LMNA mRNA 水平显著降低,提示 c.936G>A LMNA 变异导致 LMNA mRNA 减少,可能导致 LMNA 蛋白表达降低。这些发现扩展了对 LMNA 同义变异与 DCM 患者分子发病机制之间关联的认识。