Two previous surveys of ankylosing spondylitis (AS) in Mexican Mestizos found HLA-B27 frequencies of 68.6% and 78% and a relative risk (RR) of 37.05 and 120.88, respectively. We examined an additional group of Mexican Mestizos with AS and found an HLA-B27 frequency of 80.77% and a RR of 99.24. Our results are statistically comparable to the previous studies, and they suggest that the Mexican Mestizo is similar to the Spaniard in regards to AS and HLA-B27 association.
