Gluten sensitive enteropathy has various manifestations, of which the two major 
forms are classical coeliac disease (cCD) and dermatitis herpetiformis (DH). In 
cCD predominantly the small intestine is affected, whereas in DH also the skin 
is affected showing typical rash and IgA deposits. The symptoms in both forms 
are dependent on gluten intake. The factors diversifying these two clinical 
outcomes are unknown. In the present report we evaluated the role of the major 
genetic susceptibility locus, HLA DQ, in 25 families, in which both forms of the 
disease, cCD and DH, occurred in siblings. By using the family-based approach it 
can be assumed that within each family variation in environmental factors is 
substantially lower than in the standard case-control setting, and also the 
problems related to population stratification can be avoided. Results from the 
Finnish family material with 25 discordant and 85 concordant sib pairs, and from 
additional case-control material comprising 71 unrelated Hungarian DH and 68 cCD 
patients, together indicated that the HLA DQ locus did not differ between the 
two major outcomes of gluten sensitive enteropathy. The non-HLA DR;DQ factors 
are critical for the different clinical manifestations of gluten sensitivity.