Cloning and sequence analysis of 5'untranslated region of human ABO gene / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To clone and investigate the polymorphism of the 5'-untranslated region (5'-UTR) of the human ABO gene, in order to provide the basis for exploring the transcriptional regulation of the human ABO histo-blood group genes.</p><p><b>METHODS</b>ABO phenotypes of 30 unrelated healthy blood donors were determined by serological technique, their genotypes were analyzed by sequencing the exons 6 and 7 of the ABO gene. Nearly 5 kb of the 5'-UTR of ABO gene was obtained by PCR amplification and sequencing was performed bidirectionally. Haplotypes of samples with heterozygous sites in the 5'-UTR of ABO gene were separated and analyzed after cloning.</p><p><b>RESULTS</b>Twenty polymorphic sites were identified in these samples where ABO genotypes were consistent with serological phenotypes. It included sixteen nucleotide sequence variations, one 8 bp deletion, one 6 bp deletion/insertion, one 36 bp insertion and one 43 bp repeats. Among them, 11 were novel polymorphic sites. Seven different haplotypes of 5'-UTR of ABO gene were defined to the cis/trans linkage of those mutations.</p><p><b>CONCLUSION</b>There were polymorphisms in the 5'-UTR of ABO gene and the nucleotide sequences near the proximal promoter were conservative.</p>