Candidate Gene Analysis Of Alopecia Areata In Jordanian Population Of Arab Descent: A Case-Control Study

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

Genetic association of IL2RA, IL17RA, IL23R, and IL31RA single nucleotide polymorphisms with alopecia areata

The signalling of cytokine receptors plays a crucial role in regulating tolerance and immunity. Impaired immunological processes result in autoimmune inflammation that target the hair follicles, causing many hair disorders, mainly alopecia areata (AA). Therefore, polymorphisms in cytokine receptor genes are suggested to have a significant impact on the pathogenesis of AA, a disease with a multifactorial basis and uncertain etiology. In the present study, 152 AA patients of the Jordanian population were investigated for their genetic susceptibility to develop AA compared to 150 control subjects. Genomic DNA extraction and genotyping had conducted for IL17RA (rs879575, rs2229151, and rs4819554), IL2RA (rs3118470), IL23R (rs10889677), and IL31RA (rs161704) using the Sequenom MassARRAY® system. The allele frequency of IL17RA rs879575 is significantly higher in patients, while no statistical differences were found for IL2RA, IL23R, and IL31RA SNPs. Also, the recessive model of IL31RA rs161704 showing that AA genotype is significantly associated with AA development. To date, there is no published data regarding the association between AA and the selected genetic variants in our population. However, this study's findings assert that SNPs of IL17RA and IL31RA are linked to AA susceptibility in Jordanian patients.

Genetic predisposition of alopecia areata in jordanians: A case-control study

Alopecia areata (AA) is a common non-scarring hair loss disease of defined patterns with varied patches size and body sites. The etiology of AA has a complex basis of autoimmunity, environment, and genetic variations. The latter factor is found to play a crucial role in AA risk. Thus, this study aimed to investigate the potential impact of specific immune-related gene polymorphisms among a cohort of Jordanian patients, which was previously reported in other populations. Blood samples of AA patients and control subjects were collected for genomic DNA (gDNA) extraction. Targeted single nucleotide polymorphisms (SNPs) of MASP2, TLR1, CTLA4, and C11orf30 were genotyped in duplicate using the Sequenom MassARRAY® system (iPLEX GOLD). Genotype and allele analysis reveals statistical differences in TLR1 rs4833095 (allele C, P = 0.044), MASP2 rs2273346 (genotype AA, P = 0.0026), and C11orf30 rs2155219 (genotype GG, P = 0.0069) distribution. These findings present the significant contribution of genetic variations in AA susceptibility in the Jordanian population, which is infrequently studied.

MicroRNA-17-92a-1 Host Gene (MIR17HG) Expression Signature and rs4284505 Variant Association with Alopecia Areata: A Case-Control Study

Accumulating evidence indicates the implication of microRNAs (miRs) in cutaneous and hair follicle immunobiology. We evaluated, for the first time, the miR-17-92a-1 cluster host gene (MIR17HG) expression in peripheral blood of 248 unrelated alopecia areata (AA) patients compared to 244 matched controls using Real-Time qPCR. We also tested its association with different rs4284505A>G genotypes (based on TaqMan allelic discrimination PCR) and the available clinical data. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated for each genetic association model. The upregulation of miR-17 was observed in the serum of patients with alopecia compared to controls (p-value = 0.004). The ROC curve showed high diagnostic performance of miR-17 in differentiating between patients and controls (AUC = 0.85, p-value < 0.001). rs4284505*A/G heterozygotes were more susceptible to the disease (OR = 1.57, 95% CI = 1.01−2.45) under the over-dominant model. Interestingly, patients with the rs4284505*G/G genotype had a higher level of miR-17 than those with the A/A and A/G genotypes. The G/G genotype was associated with the severe phenotype (p-value = 0.038). A/G carriers were the youngest (p-value < 0.001), had more frequent scalp infection (p-value = 0.006), exhibited the worst dermatology life quality index score (p-value = 0.037), and responded less to treatment (p-value = 0.033). In conclusion, MIR17HG expression and the rs4284505 variant were significantly associated with AA and could play a role in pathogenesis and phenotype in the Egyptian population. Further multi-center studies in other ethnicities are warranted to replicate the findings.