Cannabinoid CB2 Receptor Functional Variation (Q63R) Is Associated with Multiple Sclerosis in Iranian Subjects

The cannabinoid system has been identified as a critical endogenous regulator of immune homeostasis through immunomodulatory actions. This system is one of the main regulatory systems of the central nervous system (CNS). Variations in the cannabinoid CB2 receptor gene (CNR2) could affect intracellular signaling and reduce system function, which has been associated with an unbalanced immune response and increased risk of a variety of autoimmune inflammatory disorders. The present study investigated the relationship between CNR2 rs35761398 (Q63R) functional variation and multiple sclerosis (MS). A total of 100 Iranian MS patients and 100 healthy controls were enrolled in the study and genotyped through TaqMan assay. The co-dominant, dominant, recessive, over-dominant, and additive inheritance models were analyzed using SNPStats software. A significant genetic association was observed between Q63R polymorphism and MS. The dominant model was accepted as the best inheritance model to fit the data (OR 2.70, 95% CI 1.47-4.97, p = 0.001). The data implied the involvement of the CNR2 gene in susceptibility to MS in Iranian patients.