<prompt> 13 yr old child visit OPD with complains of not attaining menarche with karyotype 46 XX. OE there is clitromegaly, which enzyme is likely deficient?17 alpha hydroxylase21 alpha hydroxylase11 alpha hydroxylase3 beta hydroxyteroid dehydrogenase  <response>: Above history point towards diagnosis of Congenital adrenal hyperplasia: - Due to deficiency of enzyme21-alpha Hydroxylase There is lack of coisol production resulting in excess of Adrenocoicotropic hormone ACTH production from pituitary. Features: - Enlarged clitoris Presence of penile urethra or hypospadias Associated metabolic abnormality -Salt wasting hyponatremia, hyperkalemia Fusion of Labia majora Lethargic hypoglycemic females. Investigations: - Karyotype is 46 XX Serum estimation Sex chromatin study reveals positive Barr body Sonographic evaluation 