Retardation of skeletal maturity can be caused by all except-

Ans is option 4 .. Congenital adrenal hyperplasia Delay in bone age is seen in - Nutritional dwarfism Hypopituitarism Hypothyroidism Renal failure In congenital adrenal hyperplasia increase in the level of sex hormones accelerates bone maturation. Ref Harrison 17/e p2208