.21 Hydroxylase Deficiency - Rapid Genetic Diagnosis, As Well As Genotypic And Phenotypic Study Of The Relationship

Objectives: 21-Hydroxylase deficiency, classified into classical type and non classic is the most common gentic metabolism disease, accounting for 90-95% of congenital adrenal disease (CAH). 21-OHD is caused by mutations of single gene (CYP21) resulting from gene conversion between CYP21 and highly homologous CYP21P (pseudogene).To investigate characteristics of CYP21 mutations in Chinese, a timesaving, reliable genotyping method is developed, and then used in study of correlation between genotype and phenotype. By our knowledge, there is no study on genotype of Chinese NC 21OHD all the world.Subjects: 43 cases 21-OHD patients (SW 8 cases, SV 26 cases, NC 21OHD 8 cases), 33 cases of obligatory carrier (parents of patients) and 20 normal controls.Methods: (1) CYP21 was amplified into fragment 1 (exonl→ exon3) & fragment 2 (exon3→ exonlO) through gene specific PCR with specific primers. Fragment 1 & 2 were digested by restriction enzyme, then mutations including P30L, E6Cluster, V281L, Q318X & R356W were detected in agarose gel. To detect mutations i2g and I172N, second round PCRs were carried out using fragment 1 & 2 as template , and PCR products were digested by Sau3AI and Nde I respectively. Products of PCR with A1/A2 primers using genome as template were digested by Taq I to examine CYP21 deletion. (2) Serum 17-OHP and F were assayed in 33 cases of obligatory carriers.