| Objective The blood group is one of the main characteristics of human blood which epresses antigen -antibody genetic characteristics of the system. More than 10 blood group systems are related to the clinical, in which ABO, Rh, Kell, Kidd and MNSs are the most important blood group systems. ABO blood group is relevant to some diseases and it plays an important role in transfusion medicine and organ transplantation, hemolytic disease, medicolegal expertise and anthropology.In general, A subtypes are more common than B subtypes. Clinically, the two most common subtypes encountered are A1 and A2. Besides these, several weaker A subtypes have been described (eg, A3, Ax, Am). Because of the weak antigenicity, the A subtypes not only have anti-B antibody, but also have different levels of anti-A, which will bring difficulties in clinical blood transfusion.At present, reports on the distribution of A subtypes are rarely in different regions, and it has not been reported in Nanjing area. The purpose was to obtain the polymorphism data of A alleles in Nanjing Han population by the larger sample size genetic analysis on A blood group, and to provide data about A blood group diversity in Chinese Han population,to rich human blood group content,to provide a basis for the study of the evolution and migration,to provide gene molecular evidence for doubtful samples on serology detected. Moreover, according to the results of subtypes survey, we will consider the feasibility of establishing ABO subtypes database to ensure the security of the clinical blood transfusion.Methods 10012 samples (7839 A samples and 2173 AB samples) were collected from the random volunteer donors of Jiangsu Province blood center from Oct,2013 to June,2014. The donors all met with the blood screening requirements. The samples were all anticoagulant by EDTA.K2. Micro-plate method was adopted to screen serology on A subtype. Collected the white layer of the weak agglutinate and inagglutinate samples was collected and reserved below-20℃ for study. Genomic DNA was isolated from EDTA blood samples by Yuan-pinghao commercial extraction kit according to manufacturer’s protocol. The exon 6-7 sequence of ABO was determined and the results were analysised by SeqScape V2.5. Based on the A101 sequence, a standard measurement sequence, the standard sequences for ABO were obtained by comparing with it and the ABO blood group genotypes were specified.Results1. In Nanjing area,the proportion of A subtype in A blood group was approximately 0.31% and the main A subtype was A201, that in AB blood group was 1.80% and the main A subtype was 205.2. Thus, it can be inferred that the ratio of either CisAB or B(A) in Nanjing Han popμlation was 4.6/100 000 and the total ratio was 9.2/100000. It was significantly higher than 1/580000-1/170000 which was previously reported by the serological method.3. A sample with a nt806 heterozygous mutation in a A205/O01 genotype was found. It was proved that the mutation was on O haploid gene by clone sequencing. The exon 7 nucleotide sequence data of the new allele was submitted to GenBank and the GenBank accession number was KP341759.4. There was no significant difference between the serological and molecular biological results for A subtype in A blood group.However, there was a significant difference in AB blood group between them.Conclusion The distribution data of blood group gene polymorphism in the Han population of Nanjing area was obtained for the first time, which will enriched the content of human blood group. The gene sequencing method set up for ABO blood group system will further improve our laboratory blood diagnostic technique. The A subtype gene bank that was preliminarily established in Nanjing can render service for difficult blood matching and blood typing,what’s more, it can receive complicated samples from other region, improve the matching success rate and ensure the safety of clinical blood transfusion. |
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