Aromatase is the enzyme responsible for the conversion of androgens to estrogen in many tissues, including the gonads and adipocytes. Increased aromatization has been reported to be a cause of familial and prepubertal gynecomastia. Kindreds have been described in whom the aromatase excess syndrome appears to be inherited in an autosomal dominant fashion, resulting in gynecomastia in boys and precocious puberty in girls, accompanied by elevations of estradiol and estrone.
