[Genetic background of rheumatoid arthritis in connection with a family tree].

Authors present a rare history of a family with accumulation of autoimmune diseases. From eight siblings four had rheumatoid arthritis, one systemic lupus erythematodes, one primary Sjögren syndrome, and one Reiter disease. Interestingly, neither the parents nor the offsprings were affected. Because of the possible genetic background, the authors performed HLA serologic and DNA investigations in nine members of the family. The results showed, in agreement with data from the literature, the accumulation of HLA-DQ7 (DQB1*0301), DR4, B27 and DR6 (DR13) risk factors. This observation confirms, that the clinical and immunogenetic features are different in familiar and sporadic forms of rheumatoid arthritis. Authors summarize the genetic background of rheumatoid arthritis in connection with this family tree.