https://orcid.org/0000-0002-9208-2087
Abstract
Background
Emery-Dreifuss muscular dystrophy, caused by mutations in genes such as emerin (EMD) or lamin A/C (LMNA), is a disorder affecting the joints, muscles, and heart, with a wide spectrum of patient phenotypes including muscle wasting and cardiac conduction defects.
Methods and results
Here we report a multi-generation family from the Hunan Province of China. Affected family members displayed an uncommon clinical presentation of serious cardiac conduction abnormalities at an early age and a high incidence of sudden cardiac death along with mild skeletal muscular atrophy and joint contracture. Clinical analysis of affected members provided evidence of X-linked recessive inheritance. Consequently, using Sanger sequencing of X chromosome exomes, we identified a novel duplication mutation (c.405dup/p.Asp136X) in the EMD gene as the cause for the disease in this family. This variant is a novel mutation that has not been previously reported in Pubmed, Clinvar or other cases reported in the Human Gene Mutation Database.
Conclusion
Our finding expands the mutation spectrum of Emery-Dreifuss muscular dystrophy and provides a rationale for EMD mutation testing in cases of X-linked inherited cardiac conduction disease and sudden cardiac death, even in those lacking pathognomonic neuromuscular features.
Acknowledgments
We would like to thank the patients and their families for participating in this study. We would also like to thank Prof. Ju Chen and Dr. Christa Trexler of University of California, San Diego, for the help in preparing this manuscript.
Statement Of Ethics
The patient (proband) provided written informed consent for the case details to be published. The study protocol has been approved by the research institute’s committee on human research.
Disclosure
The authors report no conflicts of interest in this work.