46,XX DSD due to excessive and inappropriate exposure to androgenic steroids during early gestation (i.e. congenital adrenal hyperplasia).
Likely an inhibition of 21-hydroxylase. This is the most common of the congenital adrenal hyperplasias. Presents in infancy or childhood.
Another symptom they may have that I've seen around is vomiting!! Took me a while to find it, but they are salt wasting by having no aldosterone, so the loss of electrolytes is causing increased ICP.