Distribution of an NcoI polymorphism in the lymphotoxin alpha gene in Dutch patients with inflamatory bowel diseases.

An NcoI restriction fragment length polymorphism in the first intron of the lymphotoxin alpha gene was investigated in 35 patients with Crohn's disease, 40 patients with ulcerative colitis, and 30 unrelated healthy controls, all of Dutch origin. The results showed that no significant differences existed in the genotype frequencies of the NcoI polymorphism in the first intron of the LT alpha gene between ulcerative colitis patients or Crohn's disease patients and the healthy controls. The study indicates that the NcoI polymorphism in the LT alpha gene can not be used as a genetic marker for the predisposition to inflammatory bowel diseases. However, since this polymorphism may control the production of tumor necrosis factor, study of this and other related tumor necrosis factor gene polymorphisms may be used as markers to identify patient subgroups and to define patient heterogeneity. Further studies are being carried out on other polymorphisms and on the relevance of LT alpha and TNF alpha haplotypes.