Cytochrome P450, family 19, subfamily A, polypeptide 1
Cytochrome P450, subfamily XIX (aromatization of androgens)
Flavoprotein linked monooxygenase
Catalyzes the formation of aromatic C18 estrogens from C19 androgens.
Brain, placenta and gonads.
Involvement in disease
Defects in CYP19A1 are a cause of aromatase excess syndrome (AEXS) [MIM:139300]; also known as familial gynecomastia. AEXS is characterized by an estrogen excess due to an increased aromatase activity. Defects in CYP19A1 are the cause of aromatase deficiency (AROD) [MIM:107910]. AROD is a rare disease in which fetal androgens are not converted into estrogens due to placental aromatase deficiency. Thus, pregnant women exhibit a hirsutism, which spontaneously resolves after post-partum. At birth, female babies present with pseudohermaphroditism due to virilization of extern genital organs. In adult females, manifestations include delay of puberty, breast hypoplasia and primary amenorrhoea with multicystic ovaries.