HLA-B*27 subtyping by PCR-RFLP in Spanish patients with ankylosing spondylitis

We describe the use of restriction analysis on PCR-amplified DNA for detect ing all B*27 subtypes except B*2710 and B*2711 (i.e. from B*2701 to B*2709) . After detecting B*27 by Sty,I,double digestions consisting of Sty I plus another informative enzyme led to subtype assignment We used mismatched pri mers to create restriction sites when necessary. The method avoids group-sp ecific amplifications and other laborious optimization procedures. It was s uccessfully tested on a panel of well characterized cell lines covering dif ferent B*27 subtypes. Then, Rie studied a group of 57 ankylosing spandyliti s patients and 746 controls from the south of Spain. B*27 showed a very str ong association with the disease (OR=211.27, P=10(-7)). B*2702 and B*2705 d istribution in controls (20% and 77.1%, respectively) differed from previou sly reported data in the Spanish population. We unexpectedly found the B*27 07 allele in our population (one control).