Ankylosing spondylitis without B27: no evidence for gene conversion.
Pease CT., Ellis SA., McMichael AJ., Brewerton DA.
Isoelectric focusing gel electrophoresis was used to look for variant HLA molecules in five patients with HLA-B27 negative ankylosing spondylitis (AS). The isoelectric points of the HLA-A and B antigens from these patients and HLA paired controls were identical. This implies that the HLA-A and B antigens from the patients with AS and the controls are similar. Gene conversion of a nucleotide sequence from a B27 positive gene is thus unlikely to be the explanation for the existence of AS in patients who are HLA-B27 negative by alloantisera typing.