RUNX3 and ankylosing spondylitis: Haplotype analysis based on the UK subset described in the International Genetics of Ankylosing Spondylitis Consortium Immunochip study showing the presence of four distinct RUNX3 haplotypes including rs4265380 and rs4648889. The CA haplotype has the highest risk for ankylosing spondylitis relative to the common reference CG haplotype