目的 总结新近发现的NR5A1基因突变所致46,XX卵睾性发育障碍患儿的临床特征,加深专科医生对NR5A1基因突变导致的临床疾病谱的认识.方法 报道1例由NR5A1基因杂合突变所致46,XX卵睾性发育障碍病例,并复习2016年7月以来国外报道的11例类似病例.结果 社会性别为女性的5.6岁患儿,因发现阴蒂肥大5年余就诊.患儿性腺分别位于右侧腹腔内和左侧腹股沟区,组织学均为卵睾.经探查,患儿阴道呈盲端伴子宫缺如.外院2次染色体检查均为46,XX,血SRY基因阴性,NR5A1基因c.274C>T(p.Arg92Trp)杂合突变,父母均不携带此突变.结论 本文在国内首次报道了由NR5A1基因c.274C>T(p.Arg92Trp)杂合突变所致的新表型——46,XX卵睾性发育障碍.结合文献复习,该突变呈不完全外显,在46,XX和46,XY个体均可致病,轻重程度不一.致病机制可能与突变蛋白与DNA结合障碍,导致卵巢拮抗睾丸发育因子的表达异常有关.%Objective To summarize the clinical manifestations of 46, XX ovotesticular disorder of sex development (DSD) caused by a NR5A1 heterozygous mutation. Methods The first case of 46,XX ovotesticular DSD was caused by a NR5A1 heterozygous mutation in China and was reported with a review of 11 similar cases in the literatures since July 2016. Results A 5. 6-year-old child raised as female was born with ambiguous genitalia. The left gonad was palpable in the inguinal region while the right one was located in abdomen. Gonadal histology showed both ovotestis. Vaginoscopy revealed a short, blind-ending vagina. No uterine was detected by laparoscopy. Repeated karyotype results were 46, XX with SRY gene negative. A heterozygous de novo mutation ( p. Arg92Trp) in the accessory DNA-binding region of NR5A1 gene was found in that child. Conclusions We reported for the first time in China a new phenotype caused by a NR5A1 heterozygous mutation-46,XX ovotesticular DSD. According to the review of literatures, such mutation seemed with incomplete penetrance. It could cause both 46, XX DSD and 46, XY DSD with varied manifestations. The possible underlying mechanism might relate to the impairment of the binding between the mutant protein and target DNA which might lead to a decreased inhibition of the male developmental pathway through downregulation of female antitestis genes.
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