A recurrent homozygous ACTN2 variant associated with core myopathy.
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ABSTRACT:
SUBMITTER: Inoue M
PROVIDER: S-EPMC8423689 | biostudies-literature | 2021 Oct
REPOSITORIES: biostudies-literature
Publications
A recurrent homozygous ACTN2 variant associated with core myopathy.
Inoue Michio M Noguchi Satoru S Sonehara Kyuto K Nakamura-Shindo Keiko K Taniguchi Akira A Kajikawa Hiroyuki H Nakamura Hisayoshi H Ishikawa Keiko K Ogawa Megumu M Hayashi Shinichiro S Okada Yukinori Y Kuru Satoshi S Iida Aritoshi A Nishino Ichizo I
Acta neuropathologica 20210901 4
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Project description:IntroductionDistal myopathies are a group of rare muscle disorders characterized by selective or predominant weakness in the feet and/or hands. In 2019, ACTN2 gene was firstly identified to be a cause of a new adult-onset distal muscular dystrophy calling actininopathy and another distinctly different myopathy, named multiple structured core disease (MsCD). Thus, the various phenotypes and limited mutations in ACTN2-related myopathy make the genotype-phenotype correlation hard to understand.AimsTo investigate the clinical features and histological findings in a Chinese family with distal myopathy. Whole exome sequencing and several functional studies were performed to explore the pathogenesis of the disease.ResultsWe firstly identified a novel frameshift variant (c.2504delT, p.Phe835Serfs*66) within ACTN2 in a family including three patients. The patients exhibited adult-onset distal myopathy with multi-minicores, which, interestingly, was more like a combination of MsCD and actininopathy. Moreover, functional analysis using muscle samples revealed that the variant significantly increased the expression level of α-actinin-2 and resulted in abnormal Z-line organization of muscle fiber. Vitro studies suggested aggregate formations might be involved in the pathogenesis of the disease.ConclusionOur results expanded the phenotypes of ACTN2-related myopathy and provided helpful information to clarify the molecular mechanisms.
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