Li Gui-Ji, Zhang Xu
196K Seven-year Program,China Medical University.
Liaoning Blood Center, Shenyang 110044, Liaoning Province,China. E-mail:
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2016 Oct;24(5):1563-1566. doi: 10.7534/j.issn.1009-2137.2016.05.050.
To investigate and identify the molecular and biological characteristics of B305 blood group gene subtypes of a ABO variant.
The individual was confirmed by standard serological techniques. The genotyping and sequencing were performed by using polymerase chain reaction-sequence specific primer (PCR-SSP), direct sequencing and gene cloning for Exon 6 and exon 7 of ABO locus respectively.
B antigen was detected on red blood cells of the proband and there was anti-A antibody in the serum. The PCR-SSP result showed BO1 phenotype. DNA sequencing showed 261delG, 297A/G, 425T/C, 526C/G, 657C/T, 703A/G, 796C/A, 803G/C and 930G/A heterozygote in exon 6 to exon 7. After cloning and sequencing, 2 alleles B305 and O01 were obtained. The sequence of B305 allele had one nucleotide mutation (T to C) at position 425 compared with that of B101 allele, resulting in an amino acid substitution (M142T).
T>C at nt425 of α-1,3 galactosyltransferase gene can result in B305 blood group gene subtypes, which reduce the expression of B antigen.
研究并鉴定一种ABO血型变异体B305血型基因亚型的分子生物学特征。
采用标准血清学技术对个体进行确认。分别使用聚合酶链反应-序列特异性引物（PCR-SSP）、直接测序和基因克隆技术对ABO基因座的第6外显子和第7外显子进行基因分型和测序。
先证者红细胞上检测到B抗原，血清中有抗A抗体。PCR-SSP结果显示为BO1表型。DNA测序显示第6外显子至第7外显子存在261delG、297A/G、425T/C、526C/G、657C/T、703A/G、796C/A、803G/C和930G/A杂合子。克隆测序后获得2个等位基因B305和O01。与B101等位基因相比，B305等位基因序列在第425位有一个核苷酸突变（T突变为C），导致一个氨基酸替换（M142T）。
α-1,3半乳糖基转移酶基因第425位核苷酸T>C可导致B305血型基因亚型，使B抗原表达降低。
