[Analysis of clinical phenotypes and CYP21A2 gene variants in 18 patients with 21-hydroxylase deficiency].

To explore the genotype-phenotype correlation among 18 patients with 21-hydroxylase deficiency (21-OHD).PCR-Sanger sequencing was used to analyze the 10 exons and flanking regions of the CYP21A2 gene among the 18 patients and 20 healthy controls.Seventeen patients had variants of the CYP21A2 gene. Eight patients (44.4%, 8/18) carried homozygous variants including p.Ile 173Asn (62.5%, 5/8), p.Pro31Leu (25.0%, 2/8), and IVS2-13A/C>G (12.5%, 1/8), respectively. Six patients (33.3%, 6/18) carried compound heterozygous variant, among which IVS2-13 A>G+p.Ile 173Asn were most common (50.0%). 94.4% (34/36) of the variant were pathogenic, with the most common variants being p.Ile173Asn (41.7%), IVS2-13A/C>G (19.4%), and p.Ile173Asn (7.5%). No variant was identified among the 20 healthy controls.The majority of 21-OHD patients carried CYP21A2 gene variants in homozygous or compound heterozygous forms, among which the p.Ile173Asn was the most common one. There is a strong correlation between the genotypes and clinical phenotypes.