Among our 21-OHD CAH patients, the most prevalent CYP21A2 variants were c.293-13C > G (31.4%), Del (18.6%), p.I173N (17.0%), E3 Δ8 (5.1%), p.R483PfsX58 (4.2%) and p.R357W (3.4%). The gene discussed is CYP21A2; the disease is congenital adrenal hyperplasia.