[Study on Molecular Biology of Rare Two A307 Phenotypes]

To identify the genotypes of the 2 blood samples whose serological typing were difficult by DNA sequencing analysis, and to investigate the molecular genetic basis of their genotypes.

The 2 blood samples were preliminary genotyped by PCR-SSP. The complete exon 6 and 7 in the ABO genes were amplified by PCR and the PCR products were directly sequenced and clonal sequenced in order to identify the genotypes.

The forward typing showed that both samples were weak A, while the reverse typing showed that the samples contained anti-A1. They were preliminarily genotyped as A/O1.

The sequencing analysis showed that the 2 samples contained the nt467C>T and nt745C>T mutation in the A allele, which resulted in an amino acid change from Proline (Pro) to Leucine (Leu) at codon 156 and also from Arginine (Arg) to Tryptophan (Trp) at codon 249.

Through serology results and sequencing analysis, the 2 samples are identified as rare A307 phenotypes.