Y染色体短串联重复序列(Y-short tandem repeats, Y-STRs)已被广泛应用到DNA检验领域。然而,由于Y染色体存在较高的结构突变率,可能会导致部分Y-STR等位基因丢失甚至产生特殊的缺失模式,从而影响其在法医学中的应用。位于Y染色体长臂的无精子症因子(azoospermia factor, AZF)与精子发生有关,该区域微缺失可导致不育症。然而Y染色体微缺失人群是否存在特殊的Y-STR缺失模式仍有待研究。本文利用法医学上常用17个Y-STR探讨了85例Y染色体微缺失患者的Y-STR缺失模式。结果显示,单纯AZF a区缺失样本,均存在DYS439-DYS389I-DYS389II基因座无效扩增情况;单纯AZF b区或单纯AZF c区缺失样本存在DYS448基因座无效扩增;复合AZF b+c+d区缺失样本存在DYS385-DYS392-DYS448基因座无效扩增;复合AZF a+b+c+d区缺失样本存在DYS390-Y-GATA-H4-DYS385- DYS392-DYS448基因座无效扩增。因此,本研究结果提示Y-STR缺失模式与Y染色体微缺失有对应关系。

Y chromosomal short tandem repeat (Y-STR) typing is the most commonly used genetic technique in forensic studies. However, there may be a limit to the application of Y-STR in forensic science as Y-STR loci are subject to loss or variation caused by the higher chromosomal structures’ spontaneous mutation rate. Located in the long arm of the Y chromosome, azoospermia factor (AZF) have been shown to participate in spermatogenesis and its deletion could cause infertility. However, little is known about the Y-STR dropout pattern in individuals with Y chromosome microdeletions. In this study, 85 infertile males with Y chromosome interstitial deletion were identified and special Y-STR allele dropout patterns were analyzed by employing a Y-STR Commercial Kit and a Y chromosome Deletion Kit. Results demonstrate that AZF a region deletion are related to DYS439-DYS389I-DYS389II alleles dropout, while AZF b region or c region deletions correlate to DYS448 allele dropout. Null DYS385-DYS392-DYS448 alleles were observed in AZF b+c+d region deletion individuals. While null DYS390-Y-GATA-H4-DYS385-DYS392-DYS448 alleles were observed in AZF a+b+c+d large region deletion individuals. Our data suggest that Y chromosome microdeletions may indicate specific Y-STR locus dropout patterns.