摘要5α-还原酶2型缺乏症是由SRD5A2基因的失活突变引起的,是一种常染色体隐性遗传的先天性代谢性缺陷病.由于该基因突变种类繁多,引起的酶缺乏程度各异,患者会出现不同的临床表型,从不典型的男性性征至完全的女性性征(小阴茎、会阴阴囊型尿道下裂和完全的女性表型),而且青春期开始出现男性化.这些患者的临床表型可能迥乎不同,基因型也具有多样性,临床表型与基因型的相关性依旧在深入探讨中.5α-还原酶2型缺乏症与雄激素不敏感综合征及其他46,XY性分化障碍性疾病在临床上具有相似性,应注意鉴别诊断.5α-还原酶2型缺乏症诊断依据临床表现、影像学检查、激素检测、尿类固醇分析以及基因检测等.激素诊断的参考值仍需要进一步综合研究,诊断有待于进一步规范化.多数患者在青春期前后会发生抚养性别身份从女性到男性的转变,会出现性别焦虑.患者存在性别社会认同以及其他伦理学争议.治疗方面,性别分配以及社会性别管理,诸如手术方式也有待进一步研究.该文对5α-还原酶2型缺乏症临床特点、临床表型与基因型的相关性、鉴别诊断、诊断依据以及治疗策略以及未来的挑战进行综述,以助于减轻患儿由青春期性别转换带来的痛苦,改善患儿的生活质量.

abstractsSteroid 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 characteris-tics 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 be-tween clinical phenotype and genotype is still under investigation. Steroid 5α-reductase type 2 deficiency and oth-er 46,XY disorders of sex development including androgen insensitivity syndrome have similar clinical charac-teristics,and 5α-reductase type 2 deficiency should be differentiated from other 46,XY disorders of sex develop-ment. 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 contro-versial,and surgical procedures need to be further studied. This paper reviews the clinical features,clinical pheno-type and genotype,the differential diagnosis,diagnosis basis and treatment strategy as well as the future challen-ges of 5α-reductase type 2 deficiency,in order to alleviate the sufferings caused by later gender transition in pu-berty and improve the quality of life.