Mutation detection of CYP21A2 gene in nonclassical congenital adrenal hyperplasia patients with premature pubarche

Abstract

Background: Congenital adrenal hyperplasia (CAH) due to mutations in the gene encoding 21-hydroxilase is one of common disease with an autosomal recessive form. In this study, our aim is to detect the prevalence of eight common mutations in nonclassical congenital adrenal hyperplasia (NCAH). Materials and Methods: A total of 30 patients with clinical and laboratory evidence of NCAH was selected. Gene-specific polymerase chain reaction (PCR) without contamination of pseudogene was carried out, and PCR product of this step was used to amplification-refractory mutation system PCR on eight common mutations in CYP21A2 gene. Results: Two heterozygote patients for I2G mutation and six heterozygote patients for Q318X mutation is reported in our study. These mutations associated with the classic form of CAH, and heterozygotes presented with NC symptom, including premature pubarche and hirsutism. Conclusion: There are some data about the association of the mutation with the clinical form of CAH including classic (salt-wasting and simple virilizing) and NC form. I2G and Q318X mutations were reported in classic form in homozygote state, but the heterozygote form associated with NC form. CAH diagnosis with NC symptom and with measurement of 17-hydroxyprogestrone as NCAH is not a trusted assessment and require to molecular analysis for accurate diagnosis.

Keywords

• 21-hydroxylase deficiency
• amplification-refractory mutation system polymerase chain reaction
• CYP21A2 gene
• nonclassic congenital adrenal hyperplasia