Barth syndrome is due to defect in -

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 aciduria/organic aciduria - 3-methylglutaconic acid in urine is a marker of Barth syndrome.