Dilated Cardiomyopathy and Later Onset Limb-Girdle Muscular Dystrophy Associated With Fukutin and LaminA/C Mutations

BACKGROUND: Nonischemic dilated cardiomyopathy (DCM) can result from pathogenic variants in genes affecting myocardial structure and function. FKTN and LMNA mutations may involve both cardiac and skeletal muscle, consistent with limb-girdle muscular dystrophy (LGMD), with cardiac disease sometimes preceding neuromuscular symptoms. CASE SUMMARY: We report on 2 adults presenting with advanced DCM requiring heart transplantation, who were later diagnosed with LGMD. A 22-year-old woman had biallelic FKTN variants, and a 37-year-old man carried a heterozygous LMNA pathogenic variant. Both had elevated creatine kinase prior to proximal muscle weakness. Muscle biopsy and genetic testing confirmed dystrophic processes. DISCUSSION: These cases demonstrate that genetically mediated DCM may initially present as isolated cardiac disease. Early genetic testing can guide transplant planning, long-term care, and family counseling.