Research progress of 5α-reductase 2 deficiency

Abstract

Steroid 5α-reductase type 2 deficiency is caused by mutations in the SRD5A2 gene and is a congenital metabolic defect of autosomal recessive inheritance.The variety of gene mutations causes different levels of enzyme deficiency and results in different clinical phenotype, from the typical male sexual characteristics to the complete female sexual characteristics(small penis, perineal scrotal hypospadias and complete female phenotype). In puberty, the child with 5α-reductase 2 deficiency may undergo virilization.The correlation between clinical phenotype and genotype is still under investigation.Steroid 5α-reductase type 2 deficiency and other 46, XY disorders of sex development including androgen insensitivity syndrome have similar clinical characteristics, and 5α-reductase type 2 deficiency should be differentiated from other 46, XY disorders of sex development.The diagnosis of 5α-reductase type 2 deficiency is based on clinical manifestations, imaging examination, hormone detection, urinary steroid analysis and genetic testing, etc.The cutoff value of hormonal diagnosis still needs to be studied and the diagnosis should be further standardized.In most patients, the shift from female to male will occur around puberty, and may cause gender anxiety.The patient may have gender social identity crisis and other ethical controversies.In terms of treatment, gender assignment and gender role management are controversial, and surgical procedures need to be further studied.This paper reviews the clinical features, clinical phenotype and genotype, the differential diagnosis, diagnosis basis and treatment strategy as well as the future challenges of 5α-reductase type 2 deficiency, in order to alleviate the sufferings caused by later gender transition in puberty and improve the quality of life. Key words: SRD5A2 gene; 46, XY DSD; androgen receptor; spermatogenesis; steroid 5α-reductase 2 deficiency