[ABO genotyping by PCR-direct sequencing method].

OBJECTIVE To analyze the sequence difference between human A, B, and O alleles and establish the method of ABO genotyping by PCR direct sequencing. METHODS PCR-direct sequencing technique was used to analyze two regions of cDNA from A transferase gene, 233-433 and 660-788. RESULTS Two nucleotide substitutions at 258th and 297th were found in 233-433 region, and a nucleotide substitution at 700th was found in 660-788 region. At 258th, the nucleotide was guanine in A and B alleles, and adenine in O allele. At 297th, the nucleotide was adenine in A allele, and guanine in B allele. As this position, O allele was subdivided into two types, O(A) and O(G). At 700th, the nucleotide was guanine in A and O alleles, and adenine in B allele. Therefore, 8 genotypes, AA, AO(A), AB, BB, BO(G), O(A) O(A), O(G) O(G) and O(A) O(G), could be clearly determined by only analyzing the 233-433 region. The other two genotypes, AO(G) and BO(A), could be further distinguished by analyzing the 660-788 region. CONCLUSION The technique of PCR-direct sequencing provides an effective and new method for ABO genotyping further.