Cardiolipin
Cardiolipin (diphosphatidyl glycerol) is an important component of the mitochondrial membrane, typically present in metabolically active cells of the heart and skeletal muscle. It has also been observed in certain bacterial membranes. It serves as an insulator and stabilizes the activity of protein complexes important to the electron transport chain.
Barth syndrome, a rare genetic disorder, is a mutation in the gene coding for taffazin, an enzyme involved in the biosynthesis of cardiolipin. Girls heterozygous for the trait are unaffected. Sufferers of this condition have mitochondria that are abnormal, and they cannot sustain adequate production of ATP. Cardiomyopathy and general weakness is common to these patients.