Summary

Background: Type 1 diabetes in humans is an autoimmune disease in which T cells target pancreatic islets of Langerhans, leading to the progressive destruction of the insulin-producing beta cells. Both genetic and environmental factors contribute to the development of autoimmune diabetes. The non-obese diabetic (NOD) mouse model of human type 1 diabetes demonstrates two missense mutations in the transient receptor potential vanilloid receptor-1 (TRPV1) gene.

Objectives: To investigate whether polymorphism in the TRPV1 gene may play a role in the predisposition to human type 1 diabetes.

Methods: We genotyped 146 Ashkenazi Jewish type 1 diabetic patients and 205 Ashkenazi Jewish healthy controls for the rs222747 (M315I), rs224534 (T469I) and rs8065080 (I585V) variants of the TRPV1 gene.

Results: There was a significant increase in the rs222747 (M315I) variant of the TRPV1 gene in the type 1 diabetes cohort compared to the control: rs222747 (M315I) homozygous: (61% vs. 48.3%, P = 0.02). Logistic regression analysis revealed that type1 diabetes was significantly associated with rs222747 (M315I), such that having diabetes increased the odds of rs222747 homozygosity (M315I) by 67.2%, odds ratio 1.6, 95% confidence interval 1.08–2.57, P < 0.02. No difference was found in the rs224534 (T469I) and rs8065080 (I585V) allelic variants. There was no difference in any of the TRPV1 variants by gender, age when type1 diabetes was diagnosed, body mass index, glycemic control, blood pressure, positive autoantibodies (ICA, GAD, IAA), and other autoimmune diseases.

Conclusions: Our study demonstrates that TRPV1 may be a susceptible gene for type 1 diabetes in an Ashkenazi Jewish population. These results should be replicated in the same ethnic group and in other ethnic groups.