Objectives Alopecia areata (AA) is a multifactorial autoimmune disease with a strong genetic predisposition. A variety of genes involved in immunity and inflammatory responses, such as cytokines, are suspected to increase the risk of developing AA. In which, different interleukin (IL) genes that associated with several autoimmune diseases and AA in varied populations. The objective of this study was to investigate the possible genetic association of AA with ten variants of single nucleotide polymorphism (SNP) in IL12B,IL13,IL16,IL17A, and IL18 genes among Jordanian patients. Methods In this case-control study, peripheral blood samples of 152 Jordanian AA patients and 150 controls (total of 302 subjects) were collected, genomic DNA extracted and genotyped, based on which their allele and genotype frequencies were assessed. Results In the rs11073001 SNP located in the exon region of the IL16 gene, the A allele was distributed more frequently in AA patients ( p = 0.01). A difference was found between the patients and the controls for the rs17875491 SNP in the promoter region of the IL16 gene ( p = 0.04). The mean age of onset was 27.3±12.6 with male predominance. Most patients (68.4%) were asymptomatic but some reported experiencing associated sensations before the hair loss episodes. The patchy patterns of alopecia were the most common (90.3%). Nail changes were found in 7.3% of the patients. Conclusions The findings support the hypothesis of the involvement of IL16 gene in the etiology of AA. Moreover, it emphasizes the variations in the genetic component of AA, as well as the clinical phenotypes among different ethnic groups.

BackgroundAlopecia areata (AA) is a non-cicatricial patchy hair loss on the scalp, face or other parts of the body. AA was found to be responsive to immunosuppressive therapies, a finding that supports an autoimmune basis for the disease. Several genetic studies have shown the significance of immunological factors as key genetic components in AA.ObjectiveIn this study, we aimed to investigate the genetic association of 7 single-nucleotide polymorphisms (SNPs) within five candidate genes including TAP1, CXCL1, CXCL2, HSPA1B, and TNFα with AA susceptibility in the Jordanian Arab population.MethodsA case–control genetic association study conducted in 152 patients and 150 healthy individuals was performed using the sequenom MassARRAY system (iPLEX GOLD) to genotype the selected SNPs.Resultsrs1800629 SNP of the TNFα gene was significantly associated with AA in the heterozygous and rare homozygous genotypes (P=0.022 and P=0.0079, respectively) with no linkage of the TAP1, CXCL1, CXCL2 and HSPA1B variants.ConclusionThis is the first study of its kind among the Jordanian population providing evidence of genetic association of the TNFα with AA susceptibility. Further genetic studies on Arab descent including other variants are required to clarify and strengthen the association of these genes with susceptibility to develop AA.

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