Molecular biology analysis on c. 1055G>A mutation in α-1, 3 galactosyltransferase gene responsible for ABw07 phenotype in ABO blood subgroups

Abstract

Objective To explore the molecular mechanisms for one case of ABw07 phenotype in ABO blood group system. Methods On 12th March 2014, a case of voluntary blood donor who donated blood in Qingdao Blood Center, and whose blood type was unconformity of positive and reverse ABO blood typing was chosen as a research object. Phenotype of blood sample from this donor was detected with traditional serological method. PCR-sequence specific primer (SSP) and direct sequencing methods were carried out to identify the genotypes of the sample. The exon 6 and 7 in the ABO genes were cloning sequenced to identify its haplotype. Results ① The serological test results of this donor demonstrated that the positive typing is AB, but the reverse typing is A. ② The direct sequencing of the exon 6 and 7 in the ABO genes showed that there was no deletion in nucleotide 261 and the mutations are c. 297A>G, c. 467C>T, c. 526C>G, c. 657C>T, c. 703G>A, c. 796C>A, c. 803G>C, c. 930G>A and c. 1055G>A. ③ After the cloning sequencing analysis, one nucleotide change of G to A was found, which resulted in an amino acid change from arginine to glutamine at amino acid 352 (p.Arg352Gln), the genotype of the sample was A102/Bw07. Conclusions c. 1055G>A (p.Arg352Gln) mutation of the α-1, 3-galactosyltransferase gene (B gene) is responsible for ABw07 phenotype and the serum of such individual contained anti-B. Key words: ABO blood-group system; Sequence analysis; Genotype; ABw07 phenotype; α-1, 3-galactosyltransferase