The power of the test is also increased by using the genetic information contained in the spatial ordering of single-nucleotide polymorphisms on a chromosome.<h4>Results</h4>After adjusting for the effect of population stratification, the test identified some previously discovered rheumatoid arthritis susceptibility loci (HLA-DRB1 and rs3761847) as well as some loci (rs2076530 and rs3130340) known to have association with sarcoidosis and bone mineral density. This evidence concerns the gene HLA-DRB1 and rheumatoid arthritis.