The Pro209Leu variant might affect the molecular property of the wild-type protein, as this is the most common mutation of cases described in Table 1, but our findings define new clinical features in this childhood onset myopathy and cardiomyopathy, and as a disease characterized by a spontaneous mutation in the BAG3, with neuropathy, rotatory scoliosis and osteopenia. Here, BAG3 is linked to cardiomyopathy.