Contribution of PTPN22, CD28, CTLA-4 and ZAP-70 variants to the risk of type 1 diabetes in Tunisians

This deposit is composed by a publication in which the IGC's authors have had the role of collaboration (it's a collaboration publication). This type of deposit in ARCA is in restrictedAccess (it can't be in open access to the public), and can only be accessed by two ways: either by requesting a legal copy from the author (the email contact present in this deposit) or by visiting the following link: https://www.sciencedirect.com/science/article/pii/S0378111913013462?via%3Dihub#s0060This deposit is composed by the main article, and it hasn't any supplementary materials associated.This publication hasn't any creative commons license associated.Type 1 diabetes (T1D) is caused by an immune-mediated destruction of the insulin-producing β-cells. Several studies support the involvement of T cell activation molecules. In order to underline the role of the genes involved in this pathway, we investigated, using the Sequenom MassARRAY platform, polymorphisms of sixteen single-nucleotide polymorphisms (SNPs) belonging to PTPN22, CD28, CTLA-4, and ZAP-70 genes in 76 T1D patients and 162 unrelated healthy controls from Southern Tunisia. We confirmed the association with PTPN22 (rs2476601, Corrected P (Pcorr)=0.002, OR=6.20) and CD28 gene (rs1879877, Pcorr=0.003; OR=4.27 and rs3181096, Pcorr=0.02; OR=1.73). We also identified an association with rs17695937 of ZAP-70 gene (Pcorr=0.02, OR=1.87). Our results suggest a significant effect on T1D susceptibility for A-C-A-G-C and T-C-C-T-A-C haplotypes, of ZAP-70 and CD28 genes, respectively. In addition, (A-G-C) combination of ZAP-70/CD28 gene was significantly increased in T1D patients as compared to controls, suggesting the possible interaction between these genes. These results confirm the involvement of PTPN22 and CD28 genes in the genetic susceptibility to T1D. Interestingly, ZAP-70 seems to contribute to the susceptibility to the disease in our population. However, this finding has to be confirmed in further studies.There are no funders and sponsors indicated explicitly in the document.info:eu-repo/semantics/publishedVersio

Association of BANK1 and cytokine gene polymorphisms with type 1 diabetes in Tunisia

This deposit is composed by a publication in which the IGC's authors have had the role of collaboration (it's a collaboration publication). This type of deposit in ARCA is in restrictedAccess (it can't be in open access to the public), and can only be accessed by two ways: either by requesting a legal copy from the author (the email contact present in this deposit) or by visiting the following link: https://www.sciencedirect.com/science/article/pii/S0378111913016545?via%3Dihub#ac0005This deposit is composed by the main article, and it hasn't any supplementary materials associated.This publication hasn't any creative commons license associated.Type 1 diabetes (T1D) is an autoimmune disease (AID) with both genetic and environmental components. We aimed to investigate the genetic association of polymorphisms in genes previously linked with other AIDs, namely BANK1, IL15 and IL2/IL21 region. A total of 76 T1D patients and 162 controls from Southern Tunisia were recruited for a case-control association study investigating the relationship between sixteen SNPs of the BANK1, IL15 and IL2/IL21 gene region and T1D. In the BANK1 gene, G allele and GG genotype of rs3733197 were significantly increased in the group of T1D patients compared to controls. In addition, in the IL15 gene, the minor allele A of rs10519613 polymorphism was significantly higher in patients than in controls. No significant association was found for SNPS in IL2/IL21 gene region. The analysis of the haplotype structure revealed the G-C-A-C-T haplotype of the IL15 gene as associated with a reduction in the risk of developing T1D, while A-T-A-C-T haplotype increased the risk of developing the disease. Furthermore, in the IL2/IL21 region, only one haplotype consisting of eight SNPs was markedly associated with T1D susceptibility. Moreover, G-C combination of the BANK1/IL15 was significantly increased in T1D patients, compared to controls. Our results establish BANK1 and IL15 as new T1D genetic susceptibility factors and replicate the association of the 4q27 region with T1D. Our data agree with the effect previously observed for other autoimmune conditions and delineate a shared underlying mechanism.There are no funders and sponsors indicated explicitly in the document.info:eu-repo/semantics/publishedVersio

Molecular Investigation of Distal Renal Tubular Acidosis in Tunisia, Evidence for Founder Mutations

International audienceBackground: Distal renal tubular acidosis (dRTA) is a rare genetic disease caused by mutations in different genes involved in the secretion of H+ ions in the intercalated cells of the collecting duct. Both autosomal dominant and recessive forms have been described; the latter is also associated with sensorineural hearing loss. Methods: Twenty-two Tunisian families were analyzed for mutations in the ATP6V1B1 and ATP6V0A4 genes by direct sequencing. Dating of the founder mutations was performed. Results: Two founder mutations in the ATP6V1B1 gene were found in 16/27 dRTA cases. The p.Ile386Hisfs*56 founder mutation was estimated to be older than 2400 years and no correlations were found with deafness. For the remaining patients, two mutations in the ATP6V0A4 gene, one of them being novel, were found in three Tunisian cases. The presence of a heterozygous missense mutation p.T30I, of the ATP6V1B1 gene, was identified in six patients, while no mutations of the second gene were detected. No deleterious mutations of either ATP6V1B1 or ATP6V0A were found for the two probands. Conclusion: Our study gives evidence of phenotypic and genotypic heterogeneity of dRTA in the Tunisian population. Five different mutations were found, two of them were due to a founder effect, and screening of these mutations could provide a rapid and valuable tool for diagnosis of dRTA