What is Aromatase Deficiency

Aromatase deficiency is a rare genetic disorder that affects the body’s ability to produce estrogen from androgens.  Aromatase deficiency is caused by mutations in the CYP19A1 gene, which encodes the aromatase enzyme. 

Females with Aromatase Deficiency have a typical female chromosome pattern (46,XX) but are born with external genitalia that may not appear clearly female or male, or may appear more male than female. These individuals usually have typical female internal reproductive organs, but develop ovarian cysts early in childhood, which impair the release of egg cells from the ovaries (ovulation). In adolescence, most affected females do not develop secondary sexual characteristics, such as breast growth and menstrual periods. They tend to develop acne and excessive body hair growth (hirsutism). (From Medline Plus)

Men with this condition have a typical male chromosome pattern (46,XY) and are born with male external genitalia. Some men with this condition have decreased sex drive, abnormal sperm production, or testes that are small or undescended (cryptorchidism). (From Medline Plus)

Read more basic information at https://medlineplus.gov/genetics/condition/aromatase-deficiency/