Candidate gene region 15q26 and genetic susceptibility to coeliac disease in Finnish families

Background: Studies in the Irish and British populations have indicated tha t chromosome region 15q26 could include a novel non-HLA-linked locus confer ring genetic susceptibility to coeliac disease. The locus is of particular interest, since a type I diabetes risk locus, IDDM3, maps to the same posit ion. It was tested whether this locus shows evidence for genetic linkage to coeliac disease in Finland. Methods: Ninety-nine Finnish families with at least one affected sibpair were studied. Five microsatellite markers mapped within similar to 20 cM region on chromosome 15q26 were typed. Non-paramet ric linkage (NPL) scores and allelic transmission (TDT) were studied. Resul ts: No evidence for genetic linkage could be obtained by the NPL scores cal culated by the Genehunter program. However, transmission/disequilibrium ana lysis (TDT) revealed that haplotype D15S107*1-D15S120*6 was statistically s ignificantly more frequently transmitted to affected than expected by chanc e (TDT chi (2) 9.0; P = 0.003). The subgroup of families having this haplot ype, however, did not differ from the others, regarding to disease manifest ation, HLA status, or geographical origin. Conclusion: The 15q26 region app ears not to be a major non-HLA susceptibility locus for gluten sensitivity in Finland, but a particular haplotype which may harbour a susceptibility g ene was identified.