Loss-of-function mutations in TAZ are responsible for Barth syndrome (BTHS), which is an X-linked recessive disorder characterized by cardiac and skeletal myopathies, growth retardation, hypocholesterolemia, 3-methyl glutaconic aciduria and increased susceptibility to bacterial infections due to cyclic neutropenia (Barth et al., 1983). This evidence concerns the gene TAFAZZIN and Barth syndrome.