一例罕见SRY阴性46，XX，inv(9)男性

A 46,XX SRY-Negative Male with Sex Reversal Syndrome

目的:探讨46,XX男性性反转综合征的临床表现和遗传学基础。方法:对1例46,XX,inv(9)(p11q13)男性不育患者进行系统检查,包括精液分析、血清激素和性腺组织活检,PCR法分析SRY基因和Y染色体上包括AZF区域的23个特异性位点,用FISH技术进一步证实患者核型及SRY的缺失,同时检测与性腺分化相关的SOX9和DMRT1基因内部的STR位点,以观察有无基因剂量的改变。结果:外周血淋巴细胞染色体核型分析为46,XX,inv(9)(p11q13)。Y染色体上SRY和其它23个特异位点均为阴性。未发现SOX9和DMRT1基因剂量改变。性腺组织活检证实为发育不良的睾丸组织。由于睾丸组织DNA模板提取失败,故未能检测睾丸组织的特异性位点。结论:本病例的性反转不是由SRY基因转移引起的。性别决定和分化的机制目前还不完全清楚,除了SRY等已知的基因外,可能还存在其它未知但重要的性别决定基因。

Objective： To investigate the manifestation and genetic mechanisms of the 46,XX male sex reversal syndrome. Methods： A 46,XX inv（9） infertile male was systemically examined with semen analysis, serum hormone and gonadal biopsy. The sex-determining region of the Y chromosome （SRY） gene was analyzed by the fluorescence in situ hybridization （FISH） and polymerase chain reaction （PCR）. The other 22 specific loci（including the azoospermia factor, AZF region） on the Y chromosome and the STRs of the SRY-box 9 （SOX9） and doublesex and mab-3 related transcription factor 1 （DMRT1） gene were analyzed by PCR. Results： This patient with 46, XX inv（9）（p11q13） karyotype showed male primary but without secondary sexual characters. The testis tissue was confirmed by the tissue biopsy. Absence of the SRY gene and the other 22 loci on the Y chromosome was confirmed by FISH and/or PCR in serum. The dosage of the SOX9 and DMRT1 gene was normal. Conclusion： Up to the present, the mechanism of human sex determination and differentiation is not be elucidated clearly. A unknown sex determinative gene may play the more important role in human sex determination and differentiation.