Recent advances and future vistas in treatment of diabetic retinopathy

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive disorder of bile acid synthesis which is caused by impaired hydroxylation of cholesterol sidechains due to deficiency of mitochondrial enzyme sterol 27-hydroxylase (CYP 27). This deficiency of CYP 27, which is a key enzyme in the synthesis of chenodeoxycholic bile acid, leads to storage of cholestanol and cholesterol in many tissues, especially the lens of the eye, central nervous system and tendons. The disease manifests towards the end of the first decade and progresses slowly. Laboratory diagnosis is by elevated serum cholestanol levels as well as excessive urinary excretion of bile alcohols. Four diagnostic clinical hallmarks include premature bilateral cataracts, intractable diarrhoea, neurological signs and symptoms and tendon xanthomas. We describe a 25 year old patient with bilateral cataracts, cerebellar signs, tendon xanthomas and progressive mental subnormality in whom delayed diagnosis lead to worsening of neurological symptoms.This case attempts to highlight the importance of early diagnosis and treatment of CTX, since it is a rare but one of the few treatable childhood dementias if detected early.