The present study aimed to examine and analyze cardiac involvement in two Emery‑Dreifuss
muscular dystrophy (EDMD) pedigrees caused by the c.1583 C→G mutation of the
lamin A/C gene (LMNA). The clinical and genetic characteristics of members of two families with EDMD were evaluated by performing neurological examinations, skeletal muscle biopsies, cardiac evaluations, including electrocardiography, 24 h Holter, ultrasound cardiography and 99TcM‑MIBI‑gated myocardiac perfusion imaging, and genomic
DNA sequencing. Family history investigations revealed an autosomal dominant transmission pattern of the disease in Family 1 and a sporadic case in Family 2. The three affected patients exhibited typical clinical features of EDMD, including joint
contractures,
muscle weakness and cardiac involvement. Muscle histopathological investigation revealed dystrophic features. In addition, each affected individual exhibited either
cardiac arrhythmia, which was evident as
sinus tachycardia,
atrial flutter or complete atrioventricular inhibition. Cardiac imaging revealed
dilated cardiomyopathy in two of the individuals, one of whom was presented with
heart failure. The second patient presented with no significant abnormalities in cardiac structure or function. The three affected individuals exhibited a heterozygous missense mutation in the LMNA gene (c.1583 C→G), which caused a T528R
amino acid change in the LMNA
protein. In conclusion, the present study identified three patients with EDMD, exhibiting the same dominant LMNA mutation and presenting with a spectrum of severe cardiac abnormalities, including cardiac conduction system defects,
cardiomyopathy and
heart failure. As LMNA mutations have been associated with at least six clinical disorders, including EDMD, the results of the present study provide additional mutational and functional data, which may assist in further establishing LMNA mutational variation and disease pathogenesis.