Two patients had variants in HSD17B3 and CYP17A1 genes, resulting in 17-beta hydroxysteroid dehydrogenase III (17βHSD-3) deficiency and 17-alpha hydroxylase deficiency (17OHD), respectively. The gene discussed is CYP17A1; the disease is congenital adrenal hyperplasia due to 17-alpha-hydroxylase deficiency.