This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Phospholipids, Glycolipids and their disorders, Subject name: Biochemistry
Barth syndrome is due to defect in - 
Select and explain. 
A. Thermogenic, B. Cardiolipin, C. Ubiquinone, D. Cytochrome
B: Cardiolipin
Answer: B: Cardiolipin 
Explanation: 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.