Barth syndrome (BTHS) is an X-linked potentially life-threatening recessive disease caused by mutations of a G4.5 gene in distal Xq28 (Neustein et al, 1979; Barth et al, 1983; Bolhuis et al, 1991; Bione et al, 1996), which encodes a mitochondrial transacylase named tafazzin (Neuwald, 1997; Vreken et al, 2000; Schlame et al, 2002). This evidence concerns the gene TAFAZZIN and Barth syndrome.