Ying Yanlin, Hong Xiaozhen, Xu Xianguo, Liu Ying, Lan Xiaofei, Ma Kairong, Zhu Hong, Zhu Faming, Lv Hangjun, Yan Lixing
Blood Center of Zhejiang Province, Hangzhou, Zhejiang, People's Republic of China.
Transfus Apher Sci. 2013 Feb;48(1):67-74. doi: 10.1016/j.transci.2012.08.002. Epub 2012 Sep 13.
A2 phenotype is a common subgroup of blood group A, but the serological characteristic and genetics basis of A2 phenotype currently was rare reported in the Chinese Han population. Here, a large scale study of the serology and genetics of A2 and A2B phenotypes was performed.
METHODS/MATERIALS: 11263 Chinese individuals with group A and AB phenotypes were determined for A2 antigen with the standard serological method. The full coding region of the ABO gene was sequenced in the individuals with A2 and A2B phenotypes. Some samples including each ABO genotypes were chosen for determining the activity of glycosyltransferase A (GTA) in plasma.
134 individuals were assigned as A2 and A2B phenotypes in 11263 individuals. There was imbalance in A2 and A2B phenotypes and the proportion of A2B among AB samples was significantly higher than that of A2 in group A samples. All samples of the A2 and A2B phenotypes were classified into A2-related allele group, A1-related allele group and the other group based on kind of the ABO genotype. Four novel A2-related alleles (A217, A218, A219, A220) were identified. The individuals with same genotype showed different agglutination strength with anti-A1 and anti-H on their RBCs. The plasma from individuals with A2-related allele had almost no GTA activity, while plasma from individuals with A1-related allele had some GTA activity.
A2 and A2B phenotypes could derive from different genotypes and the serological characteristic may be heterogeneity in the Chinese Han population.
A2血型是A型血的常见亚群，但目前中国汉族人群中A2血型的血清学特征和遗传基础鲜有报道。在此，我们对A2和A2B血型进行了大规模的血清学和遗传学研究。
方法/材料：采用标准血清学方法对11263例A型和AB型的中国个体进行A2抗原检测。对A2和A2B血型个体的ABO基因全编码区进行测序。选取部分包含各ABO基因型的样本检测血浆中糖基转移酶A（GTA）的活性。
在11263例个体中，134例被判定为A2和A2B血型。A2和A2B血型存在不平衡，AB样本中A2B的比例显著高于A样本中A2的比例。根据ABO基因型种类，所有A2和A2B血型样本被分为A2相关等位基因组、A1相关等位基因组和其他组。鉴定出4个新的A2相关等位基因（A217、A218、A219、A220）。具有相同基因型的个体，其红细胞上抗A1和抗H的凝集强度不同。A2相关等位基因个体的血浆几乎没有GTA活性，而A,相关等位基因个体的血浆有一定的GTA活性。
在中国汉族人群中，A2和A2B血型可能源自不同基因型，其血清学特征可能具有异质性。
