A novel EMD mutation in a Chinese family with initial diagnosis of conduction cardiomyopathy

Abstract

Introduction: Emery-Dreifuss muscular dystrophy (EDMD) is a hereditary myopathy characterized as triad of muscular dystrophy, joint contractures, and conduction cardiomyopathy. In this study, we diagnosed a X-linked recessive EDMD patient with severe conduction cardiomyopathy while noteless muscular and joint disorders.

Methods: A Chinese cardiomyopathy family spanning four generations was enrolled in the study. Targeted next-generation sequencing (NGS) was performed to identify the underlying mutation in the proband and validated by Sanger sequencing. Segregation analysis was applied to all 13 participants.

Results: A novel frameshift mutation (c.253_254insT, p.Y85Lfs*8) of emerin gene (EMD) was found and co-segregated with family members. Other than the typical manifestations of X-linked EDMD, this patient presented inconspicuous muscular disorders which were later diagnosed after the mutation been identified.

Conclusions: This study enriches the EMD gene mutation database and reminds us of the possibility of EDMD while encountering patients with severe heart rhythm defects or dilated cardiomyopathy of unknown etiology, even if they have neither obvious skeletal muscle disorder nor joint involvement.

Keywords: EMD gene; X-linked Emery-Dreifuss muscular dystrophy; conduction cardiomyopathy; novel mutation; predominant cardiac phenotype.