Less frequent types of CAH are 11β-hydroxylase deficiency (CYP11B1-D, up to 8% cases), 17α-hydroxylase/17–20 lyase deficiency (CYP17A1-D), 3β-hydroxysteroid dehydrogenase deficiency (HDS3B2-D), P450 oxidoreductase deficiency (POR-D), P450 cytochrome side-chain cleavage deficiency (CYP11A1-D), and StAR deficiency (StAR-D). This evidence concerns the gene CYP11A1 and congenital adrenal hyperplasia.