华北地区汉族人群Rh(D)抗原弱表现型个体的分子遗传机制研究

Study on the molecular genetic basis of weak D phenotypes in Han population of Northern China

目的探讨汉族人群非血缘关系Rh(D)抗原弱阳性个体的血清学表型及分子遗传机制。方法采用常规血清学技术从非血缘关系随机献血者中筛检Rh(D)抗原弱阳性个体(包括弱D型、部分D型),对其进行Rh D、C、c、E、e抗原表型的检测;采用序列特异性引物-聚合酶链反应(PCR-SSP)方法同时检测其RHD基因和RHCE基因;测序分析RHD基因全长编码区序列;同时通过特异性PCR技术测定其RHD合子型。结果血清学试验证实为D抗原弱阳性表型的有32例个体,占无关供者人群比率为0.015%,其中18例个体为弱D15型(845G>A),1例为弱D12型(830G>A),1例为携带DEL等位基因(1227G>A)的弱D型,8例为部分D表型中的DⅥⅢ型(RHD-CE(3-6)-D),1例为部分D表型中的DⅤa(Hus)(RHD-CE(5)-D),3例标本10个外显子检测均未见异常。Rh小因子检测有3种表型CcEe(4例)、Ccee(10例)、ccEe(18例),其血清学与分子生物学检测一致。RHD杂合性试验鉴定显示仅4例标本为纯合型RHD+/RHD+,其余为杂合型RHD+/RHD-。结论汉族人群D抗原弱阳性比率明显少于高加索人,汉族人群D弱表现型中,弱D15型频率最高;部分D的弱表现型中,DⅥⅢ型占主要比例。

Objective To investigate the blood group serological phenotype and the molecular genetic basis of Rh weak D individuals in Chinese Han population. Methods All samples were identified by blood group serological tests and genotyped by polymerase chain reaction-sequence specific primers （PCR-SSP）, and all 10 RHD exons were sequenced. The number of RHD was detected through PCR-SSP. Results Thirty-two samples were identified as weak D phenotype by blood group serological tests, with a frequency of 0. 015% （32/214000）. 845G〉A mutation were found in 5 weak D individuals, 1227G〉A mutation in 1, no mutation in 3; D^Ⅵ Ⅲ （RHD-CE（3-6）-D ）mutation was found in 8 partial D individuals, Dv a（Hus）（ RHD-CE（5）-D ）mutation in 1. Rh factors detected by serological test were CcEe in 4 samples,Ccee in 10 , and ccEe in 18, which was consistent with the results genotyped by PCR-SSP. RHD^＋/RHD^＋ homozygotes were detected in 4 samples, and the others were RHD^＋ /RHD^- heterozygotes. Conclusion The frequency of weak D in Chinese is much lower than that in Caucasian, 845G〉A mutation is predominant in weak D individuals, and D^Ⅵ Ⅲ mutation in partial D individuals.