The low-incidence red cell antigen Wra: genetic studies

Area of Science:

• Human Genetics
• Immunogenetics
• Molecular Biology

Background:

• The Wra antigen is a low-incidence red cell antigen.
• Its genetic basis and relationship to known blood group systems were previously uncharacterized.

Purpose of the Study:

• To perform genetic-linkage analysis of the gene responsible for the Wra red cell antigen.
• To determine if the Wra antigen belongs to established blood group systems.
• To localize the genetic locus for the Wra antigen within the human genome.

Main Methods:

• Genetic-linkage analysis was performed on 91 individuals from three families.
• The WR locus was tested for exclusion from various autosomal chromosomal regions.
• Exclusion mapping was used to assess the WR locus relative to other known genetic markers.

Main Results:

• Evidence suggests Wra is not part of the Scianna, Landsteiner-Wiener, Chido/Rodgers, or XK blood group systems.
• The WR locus was excluded from numerous specific autosomal chromosomal locations.
• Exclusion mapping indicated the WR locus is not located near specific markers on chromosomes 8, 18, 19, 20, and 22.
• The WR locus's exclusion covers approximately 10% of the human genetic map.
• The possibility of the WR locus being pseudoautosomal was deemed highly unlikely.

Conclusions:

• The gene for the Wra red cell antigen is not associated with several major blood group systems.
• The genetic locus for Wra has been significantly narrowed down through exclusion mapping.
• Further studies are needed to pinpoint the exact location and identify the gene for the Wra antigen.