Familial hypertrophic cardiomyopathy(FHC) is a complex cardiac disease with unique pathophysiological characteristics and a great diversity of morphological, functional, and clinical features. The results of molecular genetic studies have shown that FHC is a disease of the sarcomere involving eight different genes encoding proteins of the myofibrillar apparatus. Recent advances in genetic studies have provided insights into the heterogeneity of FHC clinical features. Analyses of genotype-phenotype correlations in FHC have shown that the age-related penetrance, the pattern of the left ventricular hypertrophy, and the prognosis are different depending on the disease causing genes or the disease causing mutations. Understanding of the genotype-phenotype correlations in FHC is useful for management of the disease.