Aromatase deficiency is a hormone imbalance where the female hormone estrogen is reduced, and the male sex hormone testosterone is increased.
In females, aromatase deficiency causes ambiguous external genitalia — neither clearly male nor female — at birth. The internal reproductive organs are normal, but ovarian cysts develop in early childhood. Later sexual development is also inhibited.
Males with aromatase deficiency are born with male external genitals, but some men have a decreased sex drive, low sperm production, or small or undescended testicles.
Both genders with this imbalance are abnormally tall, though bones are thinned by osteoporosis. They also both suffer from high blood sugar, excess weight gain, and fatty livers.