Rh阳性个体RHD杂合性分析

An analysis of RHD zygosity of Rh（D）-positive Chinese Han population

目的分析中国汉族Rh（D）阳性个体的RHD杂合性，讨论Rh阴性妇女产前Rh同种免疫预防策略。方法血清学检测31115名汉族捐血者的Rh（D）表型，分析Rh（D）阳性个体的RHD杂合率；对其中3628名随机Rh阳性个体采用PCR方法直接测定RHD合子型，计算杂合率与前者比较。结果31 115名捐血者中采用间接抗人球蛋白试验（indirect antiglobulin test，IAT）确认99名个体为Rh（D）阴性（0．318％），d基因频率0．05641，D基因频率0．94359，Dd杂合型0．10645（10．6％），考虑IAT检测D放散型为Rh（D）阴性，计算后实际Dd杂合型为0．09032（约9．0％）；PCR测定3628名Rh阳性个体RHD合子型测定显示DD纯合型3383人（93．2％），Dd杂合体245名（6．8％），由于无效RHD等位基因的PCR结果为阳性（D），重新分析后实际携带1条功能性RHD基因的杂合性个体约7．4％。提示中国汉族Rh（D）阴性妇女当配偶为Rh（D）阳性时，子女Rh（D）阴性的比率约3．7％～4．5％。结论中国新生儿Rh同种免疫预防进行侵入性胎儿Rh（D）血型预测意义不大，或可直接假定新生儿为Rh（D）阳性进行产前检查和同种免疫防护。

Objective To investigate the RHD zygosity of Rh（D）-positive Chinese Hans in order to study the mother-fetus Rh isoimmunization prophylaxis. Methods Rh（D） blood group of 31 115 donors were serotyped, and the RHD zygosities were analyzed, or determined through a PCR method for 3628 donors of Rh（D）-positive individuals. Results Among the 31 115 donors, 99 were tested Rh（D）-negative by indirect antiglobulin test fIAT） （0. 318%）. The d frequency was 0. 056 41, D was 0. 943 59, and Dd heterozygosity was 0. 106 45 （10.6%）. However the rate was 0. 090 32 （about 9.0%） after excluding DEL （IAT-negative）. For the 3628 PCR tested donors, 3383 were DD （93.2%）, 245 were Dd （6.8%）. After excluding nonfunctional RHD alleles, 7. 40% of the donors were carrying one functional RHD. It showed that an Rh（D）-negative Chinese Han woman gives an Rh（D） negative child at a rate of 3.7%-4.5% when her husband is Rh （D）-positive. Conclusion Fetus Rh （D）-genotyping may be unnecessary for Chinese Hans if invasive operation was needed for prenatal diagnosis. The Rh prophylaxis could be chosen assuming an Rh（D）-positive fetus.