TAFAZZIN and Barth syndrome: Barth syndrome (OMIM# 302060) is caused by mutations in TAFAZZIN. Tafazzin is responsible for the formation of mature cardiolipin (tetralinoleoyl cardiolipin; CL), an essential lipid found mainly in the mitochondrial inner membrane that stabilises multiple protein complexes for optimal function and mitochondrial health [107,108].