[Clinical phenotype and gene analysis of 86 cases of 5 alpha reductase deficiency].

Objective: Molecular genetics and clinical phenotypic characteristics of 5 alpha reductase deficiency were analyzed. Methods: The genetic results and clinical features classied as Prader grade of external genitalia of 86 children with SRD5A2 mutation seen from 2007 to 2017 at Department of Endocrinology of Beijing Children's Hospital were analyzed, and the mutation differences in different were compared regions according to the literatures. Results: Among the 86 children, 15 had were homozygous mutations, accounting for 17%, and 71 cases of compound heterozygous mutations accounted for 83%. Totally 172 alleles mutations in this series. The mutation was mainly located on exon 1 and exon 4, in which the mutation frequency of exon 1 was 23.8% (41/172), and the frequency of exon 4 mutation was 55.8% (96/172). A total of 19 mutation types of the SRD5A2 gene in this group were detected, of which 5 were new mutations (p.A228F, p.E57D, p.V124D, p.A117D, p.E197K); 65 patients had p.R227Q mutation, accounting for 76%, while 31 had p.Q6* mutation, accounting for 36%. Other rare types such as p.R246W, p.R103* and so on were also seen in the present study, there was no significant difference between north China and south China (P>0.05). The clinical phenotypes of p.R227Q variation varied, mainly in Prader 3-4, accounting for 82%, while (Prader 0-1) were less, accounting only 2%. The variation of p.Q6* was mainly manifested in Prader 3, accounting for 50%. p.R246Q mainly presented Prader 3. The variation of p.G203S appeared to have Prader 2 and Prader 4-5, accounting for 20% and 73% respectively. There was no significant difference in clinical phenotype corresponding to each protein type (P>0.05) . Conclusion: Among the 86 children have identified 19 SRD5A2 mutation types, p.R227Q is a hotspot mutation in Chinese. Variations at different types may have different clinical phenotypes, while the same variations may have different clinical features. There was no significance different in the variation types between the north and the south.