Caveolinopathies are a family of genetic disorders caused by mutations in the CAV3 gene that lead to some rare forms of hereditary myopathies during childhood [26,27] and, more rarely, contribute to cardiac diseases such as familial hypertrophic cardiomyopathy (HCM), long-QT syndrome type 9 (LQT9), sudden infant death syndrome (SIDS) and atrial fibrillation [4,13,14]. The gene discussed is CAV3; the disease is long QT syndrome 9.