Family studies in multiple sclerosis: HLA haplotypes of affected sib-pairs.

The occurrence of multiple sclerosis (MS) in several members of families has been observed in 4.8% of 105 MS patients from a limited epidemiological area of Rostock. Typing of the HLA antigens in 4 affected sib-pairs showed two identical HLA haplotypes in 3 of the pairs: 1 pair shared one haplotype. These findings point to a dominant mode of inheritance of the disease susceptibility gene together with the HLA haplotype. The assessment of family studies in MS is discussed.