Background: The red cell antigens Fra and Swa were first described in 1978 and 1959, respectively. Despite the fact that these antigens are well defined serologically, information regarding the gene(s) controlling antigenic expression was not known. The present study represents a continued effort to establish the chromosomal location of human blood group genes by family linkage studies.
Study design and methods: DNA from members of kindreds segregating for FR and SW was isolated from whole blood and analyzed for restriction fragment length polymorphisms of SLC4A1 and D17S41.
Results: Lods for linkage between FR:SLC4A1 and SW:D17S41 were determined. Peak lods of 5.72 for the FR:SLC4A1 pair and of 3.01 for the SW:D17S41 pair were observed; there was no evidence of recombination between either pair.
Conclusion: Lods for the FR:SLC4A1 and the SW:D17S41 pairs exceed the formal level required to establish linkage. (3.00) It was therefore concluded that the gene(s) governing Froese and Swann blood group polymorphism are located on the long arm of chromosome 17.