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

BACKGROUND

Studies in the Irish and British populations have indicated that chromosome region 15q26 could include a novel non-HLA-linked locus conferring genetic susceptibility to coeliac disease. The locus is of particular interest, since a type I diabetes risk locus, IDDM3, maps to the same position. 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 approximately 20 cM region on chromosome 15q26 were typed. Non-parametric linkage (NPL) scores and allelic transmission (TDT) were studied.

RESULTS

No evidence for genetic linkage could be obtained by the NPL scores calculated by the Genehunter program. However, transmission/disequilibrium analysis (TDT) revealed that haplotype D15S1071-D15S1206 was statistically significantly more frequently transmitted to affected than expected by chance (TDT chi2 9.0; P = 0.003). The subgroup of families having this haplotype, however, did not differ from the others, regarding to disease manifestation, HLA status, or geographical origin.

CONCLUSION

The 15q26 region appears not to be a major non-HLA susceptibility locus for gluten sensitivity in Finland, but a particular haplotype which may harbour a susceptibility gene was identified.