Possible association of the rs2109134 SNP within the TLR8 gene and coeliac disease

Abstract

Coeliac disease is a complex disease with multifactorial predisposing factors and in genetically predisposed individuals has an autoimmune component which is triggered by gluten. This condition affects the gastrointestinal tract causing damage to the small intestines and leads to malabsorption. Coeliac disease has an established HLA component which is responsible to 45% of the patient's genetic predisposition. The rest of the disease's genetic mechanism is thought to have a non-HLA association. TLR8 gene has been associated with the predisposition to coeliac disease in foreign studies with the tag SNP rs2109134, being associated with Crohn's Disease and Ulcerative Colitis. The aims of this study were to develop laboratory methods to identify the polymorphism in the tag SNP rs21 09134; to assess the allele frequency of the tag SNP rs2109134 amongst the Maltese population and amongst coeliac disease cases; and to determine whether there is an association between any gene variants in the tag SNP rs2109134 of the TLR8 gene and coeliac disease. This rs2109134 SNP within the TLR8 gene has been associated with the predisposition to coeliac disease in foreign studies. In this study, 300 random cord blood DNA samples and 100 samples from coeliac patients were tested for the A/T TLR8 single nucleotide polymorphism. Two different methods the tetra-primer ARMS PCR and the Type-it HRM PCR, were utilised for the detection of the SNP rs2109134. The sensitivity and specificity of these two test methods were compared in the identification of the polymorphisms. No association of the single polymorphism rs2109134 and coeliac disease was apparent in the coeliac population under study.