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Updated: May 25, 2026

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations
Published on: November 3, 2010
The functional A allele was resurrected via recombination in the human ABO blood group gene
Takashi Kitano1, Antoine Blancher, Naruya Saitou
1Department of Biomolecular Functional Engineering, College of Engineering, Ibaraki University, Hitachi, Japan. tkitano@mx.ibaraki.ac.jp
Abstract:
Functional A and B alleles are distinguished at two critical sites in exon 7 of the human ABO blood group gene. The most frequent nonfunctional O alleles have one-base deletion in exon 6 producing a frameshift, and it has the A type signature in two critical sites in exon 7. Previous studies indicated that B and O alleles were derived from A allele in human lineage. In this study, we conducted a phylogenetic network analysis using six representative haplotypes: A101, A201, B101, O01, O02, and O09. The result indicated that the A allele, possibly once extinct in the human lineage a long time ago, was resurrected by a recombination between B and O alleles less than 300,000 years ago.
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