中国汉族人群中Dia抗原和Dib抗原的分子遗传分析

目的研究中国汉族人群Diego血型系统中Dia和Dib抗原表达的分子遗传背景。方法采用血型血清学方法对2990例非血缘关系的捐血者进行Diego血型鉴定,从中随机选择20例表现型为Di(a-b )的样本,以及筛选到的所有Di(a b-)稀有血型样本,采用PCR-SSP、DNA直接测序方法分析Diego血型基因的分子遗传背景。结果2990例捐血者中,发现Di(a b-)表现型2例,Di(a b )167例,Di(a-b )2821例。随机选择的20例表现型为Di(a-b )的DNA样本,经PCR-SSP法检测的基因型为DI2DI2,对DI基因第19外显子直接测序,2561位上碱基为C。2例稀有血型Di(a b-)的DNA序列在19外显子2561位上碱基为T,基因型为DI1DI1。结论中国汉族人群Dia和Dib抗原表达的分子遗传基础是DI基因第19外显子2561位上碱基T-C的置换,引起第854位氨基酸的改变。

Molecular genetic analysis of Diego blood group Dia and Dib in Chinese Han population

Objective To study the molecular genetic background of Diego blood group in Chinese Han population.Methods A total of 2 990 blood samples from unrelated blood donors were phenotyped for Dia and Dib by serological method.Twenty randomly selected samples of Di(a-b ) type and all of the samples of rare Di(a b-) phenotype by screening were genotyped by PCR-SSP and direct DNA Sequencing.Results Of the 2 990 samples identified by serological method,2 821 were Di(a-b ),167 were Di(a b ) and 2 were Di(a b-).All of the 20 randomly-selected samples with Di(a-b ) phenotype were DI2DI2 homozygote by PCR-SSP genotyping,with nucleotide C at nt position 2 561 in exon 19 by direct sequencing of the DI gene.The 2 samples of rare Di(a b-) phenotype were both the DI1DI1 homozygote,with nucleotide T at nt position 2561 in exon 19.Conclusion Our results indicate that the expression of Dia and Dib antigens in Chinese Han population most likely result from a single nucleotide T to C substitution at nucleotide position 2561 in exon 19 of the DI gene,which subsequently leads to an amino acid 854 change from Pro to Leu.