An infant is found to have clitoral enlargement and some degree of labial fusion. What is the first step in arriving at a diagnosis?

Ans. is a, i.e. Perform a karyotypeA child born with ambiguous external genitalia could be a female who has been exposed to androgens, such as in the case of congenital adrenal hyperplasia, or a true hermaphrodite, or an under masculinized male. Such a male could have 5a-reductase deficiency, or abnormal androgen receptors, or Mullerian inhibitor deficiency. Therefore, the first step in the diagnosis is to perform a karyotype, to diagnose whether the child is a male or a female, because further investigations would depend on the genetic sex. However, a true hermaphrodite could be XX or XY.