[Heredity and immunology in Sjogren's syndrome]

Over the next 3-5 years, the rapid progress in genomic research will enable the discovery of many genes associated with the more common diseases. An example of such a common disease is the rheumatic disorder Sjögren's syndrome, an autoimmune disease. A more precise genetic explanation of the mechanism leading to Sjögren's syndrome remains to be given.

One way of investigating the disease related genes in such complex polygenic diseases is to perform linkage studies in families with two or more affected. Another possibility is to conduct association studies on trios (parents and affected child), case control studies, or other experimental designs. In association studies one is testing if an allele is significantly elevated among patients compared to controls, while in linkage analyses one finds subchromosomal regions that are significantly more often inherited by patients than by healthy family members.

The most well defined genetic association in Sjögren's syndrome is currently related to different HLA alleles and their association with anti-Ro/SSA and anti-La/SSB autoantibodies. Additional genetic studies focusing on non-HLA regions are under way.

Increased genetic knowledge would allow optimisation of the diagnostic criteria as well as development of new and more effective treatment for Sjögren's syndrome, which causes substantial suffering for a large group of patients.