LMNA-associated congenital muscular dystrophy (L-CMD) is a severe form of muscle laminopathy. LMNA encodes lamin A, which an intermediate filament protein that attaches to the inner membrane of the nuclear envelope. We performed sequence analysis based on our original targeted gene panel system for muscle diseases to obtain a molecular diagnosis in a Japanese girl with L-CMD. A novel heterozygous missense mutation, c.115A>C (p.Asn39His), in LMNA is reported.