GENETIC-FACTORS IN MULTIPLE-SCLEROSIS

Epidemiological studies have provided evidence for a genetic contribut ion to the susceptibility of multiple sclerosis (MS). One in six patie nts has at least one affected family member. The concordance rate is a pproximately 25% in monozygotic twins, and 3% in siblings, however the prevalence in adopted siblings is similar to the general population ( 0.1%) MS is thought to be a T cell-mediated autoimmune disease and the refore genes controlling the immune response have been studied intensi vely as potential susceptibility factors. The best documented associat ion was found for genes of the human-leukocyte antigen complex. Other possible susceptibility genes may reside in the regions of the T cell receptors and the tumour necrosis factors. So far it is clear, that MS is a multifactorial disease in which several genes must be involved. Population genetics and molecular biology will help to characterise fu rther these susceptibility factors.