Linkage between T cell receptor genes and susceptibility to multiple sclerosis: a complex issue.

Susceptibility to Multiple Sclerosis (MS) and to other autoimmune diseases has been linked to genes encoded within the HLA complex. More recent evidence indicates linkage between MS and genes encoded within or closely linked to the T cell receptor (TCR) beta chain gene complex. However, not all available data are concordant. Discrepancies are most likely rooted in the complex nature of TCR and MHC genes and interactions of their products in initiating and sustaining autoimmune responses. An evaluation of linkage of TCR and MHC genes to autoimmune disease processes must take into account the nature of polymorphism in the gene complexes, the complexity of autoimmune diseases along with the multigenic nature of genetic predisposition. These factors create a situation in which simple genetic linkage may be the exception rather than the rule. The present report reviews data concerning TCR and MS linkage and enumerates the complexities that arise in evaluating results from such studies.