Association of PTPN22 Single Nucleotide Polymorphisms with Celiac Disease

Understanding the Genetic Basis of Celiac Disease: A Comprehensive Review

Celiac disease is an immune-mediated enteropathy with typical symptoms of weight loss, abdominal bloating, diarrhea, vomiting, or constipation. Many shreds of evidence show that CeD is hereditary in origin and various biochemical pathways have been connected to its etiology. Numerous genes from different physiological pathways have been investigated in the last few decades, however a comprehensive analysis is required to address the gaps and provide a more integrated understanding of how these genetic factors contribute to the pathogenesis of disease. Present study attempts to summarize the historical and up-to-date findings to understand the role of genetics in Celiac disease. The literature was searched from sources such as PubMed and Google Scholar to analyze studies conducted on celiac disease from the years 1995 to 2024. Term maps were created to examine the frequency of studies related to various terms to understand the major focus of the studies till date. The study also concise the different genetic polymorphisms studied in a table to understand the role of genetics in celiac diseases. Early studies on celiac disease primarily focused on its pathophysiology, prevalence, and general aspects, with limited attention to genetics. However, recent studies have increasingly emphasized the genetic basis of the disease and highlighting the involvement of various pathways like inflammation, T-cell differentiation and activation, epithelial barrier function, stress and apoptosis pathways. However, present study indicate that most current research predominantly focus on cytokines, specifically the TNF alpha gene. Consequently, there is a need for additional research to gain a more comprehensive understanding of the genetics of celiac disease.

PTPN22 intron polymorphism rs1310182 (c.2054-852T>C) is associated with type 1 diabetes mellitus in patients of Armenian descent

Protein tyrosine phosphatase, nonreceptor type 22 (PTPN22), is an archetypal non-HLA autoimmunity gene. It is one of the most prominent genetic contributors to type 1 diabetes mellitus outside the HLA region, and prevalence of its risk variants is subject to enormous geographic variability. Here, we address the genetic background of patients with type 1 diabetes mellitus of Armenian descent. Armenia has a population that has been genetically isolated for 3000 years. We hypothesized that two PTPN22 polymorphisms, rs2476601 and rs1310182, are associated with type 1 diabetes mellitus in persons of Armenian descent. In this association study, we genotyped the allelic frequencies of two risk-associated PTPN22 variants in 96 patients with type 1 diabetes mellitus and 100 controls of Armenian descent. We subsequently examined the associations of PTPN22 variants with the manifestation of type 1 diabetes mellitus and its clinical characteristics. We found that the rs2476601 minor allele (c.1858T) frequency in the control population was very low (q = 0.015), and the trend toward increased frequency of c.1858CT heterozygotes among patients with type 1 diabetes mellitus was not significant (OR 3.34, 95% CI 0.88-12.75; χ2 test p > 0.05). The control population had a high frequency of the minor allele of rs1310182 (q = 0.375). The frequency of c.2054-852TC heterozygotes was significantly higher among the patients with type 1 diabetes mellitus (OR 2.39, 95% CI 1.35-4.24; χ2 test p < 0.001), as was the frequency of the T allele (OR 4.82, 95% CI 2.38-9.76; χ2 test p < 0.001). The rs2476601 c.1858CT genotype and the T allele correlated negatively with the insulin dose needed three to six months after diagnosis. The rs1310182 c.2054-852CC genotype was positively associated with higher HbA1c at diagnosis and 12 months after diagnosis. We have provided the first information on diabetes-associated polymorphisms in PTPN22 in a genetically isolated Armenian population. We found only a limited contribution of the prototypic gain-of-function PTPN22 polymorphism rs2476601. In contrast, we found an unexpectedly close association of type 1 diabetes mellitus with rs1310182.

Protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene polymorphisms in liver transplant donors and impact on acute cellular liver transplant rejection

The PTPN22 gene encodes the lymphoid protein tyrosine phosphatase involved in regulation the immune response. The single nucleotide polymorphisms (SNPs) rs1217388, rs1310182, rs2476601, and rs2488457 are located within the PTPN22 gene. We investigated whether these SNPs in liver transplant donors are associated with acute cellular rejection in the recipients. The SNPs were analyzed in donors (n = 104) of recipients who did not develop an acute cellular rejection and in donors (n = 53) of corresponding recipients developing an acute cellular rejection. No significant differences in genotype and allele frequencies of these SNPs were detected in either of the group. Our data suggest that these SNPs in liver transplant donors have no impact on the susceptibility of acute cellular liver transplant rejection.