<prompt> Barth syndrome is due to defect in -ThermogenicCardiolipinUbiquinoneCytochrome  <response>: Ans. is b i.e., Cardiolipin o Barth syndrome is an X-linked recassive disorder due to mutation in tafazzin gene TAZ.o The mutation leads to abnormal structure or deficiency of cordiolipin, a mitochondrial structural phospholipido This results in mitochondrial dysfunction.o The clinical features are :- Hypothyroidism Dilated cardiomyopathy Developmental delay Heart failure Neutropenia Muscle weakness Diabetes Muscle weaknese hypotoniao There is 3-methyl glutoconic aciduriaorganic aciduria - 3-methylglutaconic acid in urine is a marker of Barth syndrome. 