广州地区无偿献血者人群中Jk(a-b-)表型筛选及分子遗传学研究

Study on the frequency of distribution and molecular genetic background of Jk(a-b-)donors in Guangzhou

目的了解广州地区无偿献血者人群中,Kidd血型系统中Jk(a-b-)稀有血型个体的分布频率及分子遗传背景。方法用2 mol/L尿素溶解法,对50 000名广州血液中心无偿献血者中的Jk(a-b-)血型个体进行筛选。用传统的血型血清学方法对筛选到的Jk(a-b-)表型进行确证。随后从静脉血中提取DNA,PCR方法扩增Kidd血型系统编码基因Jk的所有编码外显子,并直接进行测序分析。结果在50 000名无偿献血者中共筛选到10名Jk(a-b-)血型个体,在广州地区无偿献血者人群中其分布频率约为0.02%。在对其中8名先证者基因分型中,共发现了2种基因型,纯合IVS5-1G>A(n=6),杂合IVS5-1G>A/杂合896G>A(299Gly>Glu)(n=2)。结论广州地区无偿献血者人群中,Jk(a-b-)的分布频率高于已报道的北方人群。高频率分布于太平洋波利尼西亚群岛的变异IVS5-1G>A,也是本人群中最常见的基因变异。

Objective To study the frequency of distribution and molecular genetic background of Jk（a-b-） donors in Guangzhou. Methods Blood samples were collected from 50 000donors in Guangzhou Blood Center. Urea lyses method was used to screening the Jk （a-b-） individuals. Then the phenotype was confirmed by the standard serological meth- ods. DNAs were extracted from venous blood. PCR method was adopted to amplify the coding exons of Jk gene and then PCR products were sequenced directly. Results Ten donors with Jk （a-b-） phenotype were screened from 50 000 donors and the frequency of Jk（a-b-） was 0. 02%. Eight DNA samples were available to sequencing Jk gene. Two genotyping re- sults（homozygous IVSS-1G 〉 A, n = 6; heterozwous IVSS-1G 〉 A/heterozv,,ous 896G 〉 A n = 2）were identifled. Conclusion The frequency of Jk （a-b-） in Guangzhou blood donors is higher than the reported from populations in Northern regions of China. The IVSS-1 G 〉 A mutation, distrib- uted in Polynesians with high frequency, is also the most com- mon variations identified in Guangzhou populations.