Genetic analysis in Italian families with inflammatory bowel disease supports linkage to the IBD1 locus - A GISC study

Epidemiological studies suggest that inherited factors influence susceptibi lity to inflammatory bowel disease (IBD), and some candidate loci have been described, In order to verify whether the same loci are responsible for pr edisposition to IBD in our population, we carried out a linkage study in a series of 58 Italian families with Crohn's disease (CD) and ulcerative coli tis (UC), HLA-DQ alleles, motilin gene, and 34 microsatellites flanking the previously described loci on chromosomes 3, 6, 7, 12 and 16 were analysed by non-parametric linkage analysis in 16 and 23 families with CD and UC, re spectively, and in 19 families where CD and UC coexisted. Non parametric an alysis using GENEHUNTER yielded maximum NPL scores for marker D16S408 in al l LED families combined (2.71, P = 0.003), for marker D16S419 in CD (1.97, P = 0.026) and for marker D16S514 in UC families (2.44, P = 0.007), These m arkers map in the previously described IBD1 region, No significant linkage was found for markers of chromosomes 3, 6, 7 and 12. The present study perf ormed in a Southern European population provides additional support for the conclusion that the IBD1 locus has a clear role in the genetic susceptibil ity to IBD.