Autoimmune stigmata in Turner syndrome: when lacks an X chromosome.

An increased frequency of autoimmune diseases as well as an elevated incidence of autoantibodies has been observed in patients with Turner syndrome; the most common autoimmune diseases appear to be thyroid autoimmune disease and inflammatory bowel diseases. Turner patients evolve towards autoimmunity much more frequently than people with normal karyotype without any relevant excess of the putative immunogenetic risk markers. That underscores the great influence of X-chromosome abnormalities in the development of autoimmune disorders and suggests an epistatic interaction of X genes with immune response genes. Interestingly, one of the human MHC-paralogues is located in the long arm of the X chromosome, so that who is defective in this region might be less efficient to control the pathogenic repertoire during the lifespan. Medical care for patients with TS should routinely include screening for the autoimmune disorders in order to assure early detection and appropriate treatment.