Genetic Polymorphisms of Immunity Regulatory Genes and Alopecia Areata Susceptibility in Jordanian Patients.

Background and Objectives: Alopecia areata (AA) is a tissue-specific immune-mediated disorder that affects hair follicles and the nail apparatus. Due to the collapse of hair follicle immune privilege in AA, hair loss ranges in severity from small, localized patches on the scalp to the loss of entire body hair. Although AA is of uncertain etiology, the disease has a common genetic basis with a number of other autoimmune diseases. Materials and Methods: To identify candidate genes that confer susceptibility to AA in the Jordanian population and further understand the disease background, we performed DNA genotyping using case-control samples of 152 patients and 150 healthy subjects. Results: While no significant result was observed in the ten single-nucleotide polymorphisms (SNPs), CLEC4D rs4304840 variants showed significant associations with AA development within our cohort (p = 0.02). The strongest associations were for the codominant and recessive forms of rs4304840 (p = 0.023 and p = 0.0061, respectively). Conclusions: These findings suggest that CLEC4D gene variants may contribute to AA pathogenesis among Jordanians. Further advanced genetic analysis and functional investigations are required to elucidate the genetic basis of the disease.