MAPPING OF A SUSCEPTIBILITY LOCUS FOR CROHNS-DISEASE ON CHROMOSOME-16

Crohn's disease (CD) and ulcerative colitis are the major forms of chr onic inflammatory bowel diseases in the western world, and occur in yo ung adults with an estimated prevalence of more than one per thousand inhabitants'. The causes of inflammatory bowel diseases remain unknown , but genetic epidemiology studies(2-5) suggest that inherited factors may contribute in part to variation in individual susceptibility to C rohn's disease. A genome-wide search performed on two consecutive and independent panels of families with multiple affected members, using a non-parametric two-point sibling-pair linkage method, identified a pu tative CD-susceptibility locus on chromosome 16 (P < 0.01 for each pan el). The localization was centred around loci D16S409 and D16S419 by u sing multipoint sibpair analysis (ref. 6, and J.M.O., manuscript submi tted) (P < 1.5 x 10(-5)). This region of the genome contains candidate genes which may be relevant to the pathogenic mechanism of inflammato ry bowel diseases.