CYP21A2 Gene Diagnosis Of Congenital Adrenal Hyperplasia

Objective:To explore the advantage and reliability of restrictive endonuclease digestion analysis and direct sequencing in the CYP21A2 gene mutations of congenital adrenal hyperplasia (CAH), and provide basis for genetic counseling and prenatal diagnosis of this disease.Methods:Peripheral blood DNA samples were collected from 7 pedigrees of congenital adrenal hyperplasia. CYP21A2 gene segments amplified by PCR using special primers were used to identify the mutations I172N, i2g, Del, P30L, Q318X, V281L, E6Cluster, R356W and Exon3 Del8 bp by restriction endonuclease digestion. Those cases who could not be determined were further analyzed the all exons and introns of CYP21A2 gene by direct sequencing analysis.Results:The common mutations of the CYP21A2 gene including i2g, Q318X, Del, Exon3Del8bp, R356 and so on were detected by PCR-restriction endonuclease digestion in the 7 congenital adrenal hyperplasia pedigrees. i2g and I172N mutations were further detected in some patients who could not determined by PCR sequencing analysis. Q318X mutation combining with CD387 AAC→AAA was detected from a salt wasting children patient.Conclusion:PCR-sequencing analysis is a valuable supplement of PCR-restriction endonuclease digestion for CYP21A2 gene mutations of congenital adrenal hyperplasia.. For common mutations such as i2g and I172N as well as some uncommon ones, PCR-sequencing analysis can more effectively in improving detection rate and the accuracy of CAH diagnosis than PCR-restriction endonuclease digestion.