The commonest cause of primary amenorrhea with ambiguous genitalia in a female with 46XX chromosome

Ans. is 'a' i.e. 21-hydroxylase deficiency Primary amenorrhoea with virilization (ambiguous genitalia) in females is seen in21 hydroxylase def.11 hydroxylase def17-hydroxylase def. does not cause virilization. It causes in females- Primary amenorrhoea and failure of development of secondary sexual characteristics."21-hydroxylase and 11-hydroxylase deficiencies are common; the former accounts for 90-95% of the cases of congenital adrenal hyperplasia, and the latter accounts for all but 1% of the remaining cases."Also know this*Congenital adrenal hyperplasiaIs commonly caused by there 4 enzyme deficiencies.21 hydroxylase def. (Complete)21 hydroxylase def. (Partial)11 hydroxylase def.17 hydroxylase def.21 hydroxylase def. Complete (Salt loosing virilizing)*Hypotension*Virilization (& Precocious puberty in males)*21 hydroxylase def. partial (Simple virilizing)*Normal B.P.*Virilization* (& Precocious puberty in males)*11 hvdroxvlase def.Hypertension*Virilization* (& Precocious puberty in males)*17 hvdroxvlase def. hypertension*Hypertension*No virilization in females*Primary amenorrhoea and failure of development of sec. sec. characteristics in females*Male hermaphrodites*