EVIDENCE FOR FAMILIAL AGGREGATION IN SIBLINGS WITH AUTOIMMUNE RHEUMATIC DISEASES

Autoimmune rheumatic disorders have a multifactorial determinism, caused by various environmental factors acting on the individual’s genetic susceptibility, destabilizing the systems which regulate the immune response. Epidemiological and genetic investigations are very important to demonstrate the contribution of genetic factors to the development of these autoimmune diseases. The contribution of genetic factors in causing autoimmune diseases has been demonstrated by familial aggregation. Moreover, it was also quantified by determining heritability, expressing the proportion of genetic factors in the etiology. It is now clear that common genes underlie multiple autoimmune disorders.