CYP21A2 and congenital adrenal hyperplasia: In the present study, we recruited 70 infants and children with PAI and sequentially performed CYP21A2 gene Sanger sequencing, MLPA testing and biochemical analysis plus detailed clinical examinations and found an overall 84.3% (59/70) diagnostic rate for CAH, with 91.5% (54/59) of CAH patients showing positive genetic findings.