A 3·0-kb deletion including an erythroid cell-specific regulatory element in intron 1 of the ABO blood group gene in an individual with the Bm phenotype

We developed a sequence-specific primer PCR (SSP-PCR) for detection of a 5·8-kb deletion (Bm5·8) involving an erythroid cell-specific regulatory element in intron 1 of the ABO blood group gene. Using this SSP-PCR, we performed genetic analysis of 382 individuals with Bm or ABm. The 5·8-kb deletion was found in 380 individuals, and disruption of the GATA motif in the regulatory element was found in one individual. Furthermore, a novel 3·0-kb deletion involving the element (Bm3·0) was demonstrated in the remaining individual. Comparisons of single-nucleotide polymorphisms and microsatellites in intron 1 between Bm5·8 and Bm3·0 suggested that these deletions occurred independently.