广州献血人群中A_(2)亚型的分布及分子机制研究

Distribution and molecular basis of A_(2) subtype in Guangzhou blood donors

目的调查A_(2)亚型在广州献血者人群中的分布,并研究其分子基础。方法随机抽取广州地区A型自愿无偿献血者全血标本793例,利用抗-A1凝集素在96孔板中筛查献血者中的A_(2)亚型,再用试管法对检出的A_(2)亚型标本进行ABO正反定型确证。然后,提取A_(2)亚型献血者静脉血基因组DNA,并对ABO基因外显子6和7进行测序以明确A_(2)亚型的基因型。结果793例A型献血者中A_(2)亚型有13例,在A型献血者中的频率为1.64%(13/793)。ABO基因外显子6和7测序结果显示13例A_(2)亚型中10例携带有A_(2)等位基因,分别是ABO^(*)A_(2).05/ABO^(*)O.01.01(n=5),ABO^(*)A_(2).05/ABO^(*)O.01.02(n=2),ABO^(*)A_(2).01/ABO^(*)O.01.01(n=1)及ABO^(*)A_(2).01/ABO^(*)O.01.02(n=2),另外有3例只携带有ABO^(*)A1.02等位基因。结论广州地区A_(2)亚型献血者基因型以ABO^(*)A_(2).05为主,其次为ABO^(*)A_(2).01。

Objective To investigate the distribution and molecular basis of A_(2)subtype among blood donors in Guangzhou.Methods Whole blood samples of 793 group A blood donors in Guangzhou Blood Center were randomly collected.A_(2) subtype was screened by anti-A1 lectin in 96-well plate,and ABO typing was confirmed by the tube test.Then,the genomic DNA of A_(2) subtype blood donors was extracted,and the exons 6-7 of ABO gene were sequenced to determine the genotype of A_(2) subtype.Results Among 793 group A blood donors,there were 13 cases of A_(2) subtype,and the frequency in group A was 1.64%(13/793).The sequencing results of exons 6-7 of ABO gene showed that 10 of the 13 A_(2) subtypes carried A_(2) alleles,which were ABO^(*)A_(2).05/ABO^(*)O.01.01(n=5),ABO^(*)A_(2).05/ABO^(*)O.01.02(n=2),ABO^(*)A_(2).01/ABO^(*)O.01.01(n=1)and ABO^(*)A_(2).01/ABO^(*)O.01.02(n=2),respectively.The other 3 cases only carried ABO^(*)A1.02 alleles.Conclusion The main genotype of A_(2) subtype in Guangzhou is ABO^(*)A_(2).05,followed by ABO^(*)A_(2).01.