Homozygous Nonsense Mutation p.Q274X in TRIM63 (MuRF1) in a Patient with Mild Skeletal Myopathy and Cardiac Hypertrophy.

TRIM63 mutations have been described as a potential cause for cardiac and skeletal myopathy in only one family so far. We describe a new patient carrying the same homozygous TRIM63 nonsense mutation c.739 C>T p.Q247X, that was originally reported in two members of a Spanish family manifesting cardiac hypertrophy. One of these original patients also had an additional heterozygous mutation in TRIM54 and a much more severe phenotype also involving skeletal muscles, and a digenic inheritance was therefore suggested. Our case report confirms the role of TRIM63 as a new cardiac myopathy gene, although it is unclear whether the homozygous p.Q247X mutation alone is sufficient to cause an additional skeletal myopathy.