CYP11A1 and hypogonadotropic hypogonadism: For example, boys with X-linked adrenal hypoplasia (NR0B1/DAX-1) are at risk of developing hypogonadotropic hypogonadism in adolescence, whereas there is a potential risk of long-term sex steroid insufficiency or hypofertility with partial defects in STAR or CYP11A1/P450scc [7,25,35,36,46].