HLA-DRB1-DQB1 genotypes from 2,555 multiple sclerosis patients, protective-predisposing nature for haplotypes in the second column, OR values of the individual haplotype (ORha and ORhb), the genotypic value of OR expected under log-additivity model (ORgexp) and the observed one (ORgobs), values of

Rare haplotypes belonging to the same haplogroup were grouped together: as *11 were designed *11∶01-02-03-04 -*03∶01, *11∶01-*03∶03-*05∶02 and *11∶04-*06∶03; as *07 were designed *07∶01- *02∶01 and *07∶01-*03∶03.