Identification of a new quantitative trait locus on Chromosome 7 controlling disease severity of collagen-induced arthritis in rats

Autoimmune diseases, such as rheumatoid arthritis, Crohn's disease, and mul tiple sclerosis, are regulated by multiple genes. Major histocompatibility complex (MHC) genes have the strongest effects, but non-MHC genes also cont ribute to disease susceptibility/severity. In this paper, we describe a new non-MHC quantitative trait locus, Cia8, on rat Chromosome (Chr) 7 that con trols collagen-induced arthritis severity in F2 progeny of DA and F344 inbr ed rats, and present an updated localization of Cia4 on the same chromosome . We also describe the location of mouse and human genes, orthologous to th e genes in the genomic intervals containing Cia4 and Cia8, and provide evid ence that the segment of rat Chr 7 containing Cia4 and Cia8 is homologous t o segments of mouse Chr 10 and 15 and human Chr 8, 12, and 19.