Although the evidence for linkage of coeliac disease to chromosome 15q26 is not strong, the well established association between coeliac disease and insulin dependent diabetes mellitus, together with the mapping of an IDDM susceptibility locus (IDDM3) to chromosome 15q26, provide indirect support for this as a candidate locus conferring susceptibility to coeliac disease in some families.
Affected sibling pair linkage analysis revealed strong evidence for an IDDM susceptibility locus near D15S107 on chromosome 15q26 (P = 0.0010) termed IDDM3.