Background Laminopathies caused by LMNA gene mutations are characterized by different clinical manifestations. Among them, cardiac involvement is one of the most severe phenotypes. Case presentation A 30-year-old man visited the hospital because of palpitations, shortness of breath, and fatigue. He also had muscular dystrophy, joint contractures, scoliosis, and mild dysphagia. A novel de novo heterozygous LMNA splice variant (c.810+1G>T) with dilated cardiomyopathy, Emery-Dreifuss muscular dystrophy, and progressive cardiac conduction defect was identified by genetic analysis. The patient also presented with congenital aortic valve malformation, which has never been reported in laminopathies. Conclusions The LMNA mutation (c.810+1G>T) was identified for the first time, enriching the mutation spectrum of the LMNA gene. The correlation between an LMNA mutation and congenital aortic valve malformation deserves further study.