Gm typing of Irish coeliac patients and controls does not help locate the "second" coeliac gene

Susceptibility to coeliac disease in Tunisian children and GM immunoglobulin allotypes

Coeliac disease is a malabsorption disorder of the small intestine resulting from ingestion of gluten. The immunogenetic component is clearly demonstrated by the association of the disease with human leukocyte antigens (HLA). Among other candidate genes are the GM allotypes, which are the markers of the constant parts of heavy chains of the subclasses IgG1, IgG2 and IgG3. GM immunoglobulin allotypes have been analysed in 131 unrelated Tunisian children with coeliac disease. All patients and their parents were tested for G1M(1, 2, 3, 17), G2M(23) and G3M(5, 6, 10, 11, 13, 14, 15, 16, 21, 24, 28) by the classical haemagglutination method. Genotypes and haplotypes were deduced from phenotypes in patients and their parents. Transmission disequilibrium tests were performed in 79 informative families. The GM*3;..;5* haplotype was transmitted more often (23) than not (8) by heterozygous parents (chi 2 = 7.26; P = 0.007). This difference remained significant after correction for multiple testing. This study provides evidence for association and linkage between GM and coeliac disease. It suggests that GM or genes close to GM play a role in the development of the disease.

Lewis phenotype, secretor status, and coeliac disease

Patients who cannot secrete ABO and Lewis blood group antigens into body fluids, an ability controlled by a single gene on chromosome 19, are known to be at increased risk of certain autoimmune diseases associated with human leucocyte antigen (HLA) markers. This study investigated the possibility of an association with coeliac disease using red cell Lewis (Le) blood group phenotype to infer secretor status. Among 73 patients with coeliac disease who had Le a or b antigen, 48% were non-secretors (Le a + b-) compared with 27% of 137 blood donors (p = 0.004: odds ratio 2.49, 95% confidence intervals 1.37 to 4.51) and 26% of 62 medical and nursing staff controls (p = 0.014: odds ratio 2.65, 95% confidence intervals 1.27 to 5.50). Clinical characteristics did not differ between secretors and non-secretors with coeliac disease. Thus, the non-secretor state is significantly associated with coeliac disease, suggesting that genes on chromosome 19 may directly or indirectly participate in conferring susceptibility.