Multiple sclerosis (MS [MIM 126200]) is a chronic inflammatory disease of the central nervous system. Whereas the etiology of MS is likely to be heterogeneous, the influence of genetic factors in the development of MS has been confirmed by association and linkage studies.1, 2, 3, 4 The crucial role of HLA alleles in the susceptibility to MS is well established. Whereas HLA-DRB1∗15 alleles are strongly associated with MS in Europeans, DRB1∗0301 and DRB1∗0401 are overrepresented in MS patients from southern Europe.5, 6 Overrepresentation of DRB1∗04 alleles was reported for patients from Turkey and the Canary Islands. Although the genetic association of susceptibility to MS with loci outside the HLA complex has been confirmed in some cases, the search for susceptibility genes continues.4