CTLA4 +49AG (rs231775) and CT60 (rs3087243) gene variants are not associated with alopecia areata in a Mexican population from Monterrey Mexico

Association between the CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants with vitiligo: Study on a Mexican population

Background

Vitiligo is characterized by an autoimmune response targeting melanocytes, thus resulting in skin depigmentation. There are several genetic components involved in the development of vitiligo, of which various gene polymorphisms are currently considered as risk factors. For example, the CTLA4 (T-lymphocyte antigen 4) +49A/G (rs231775) and CT60 (rs3087243) gene variants have been associated with a predisposition for autoimmune diseases in different populations; however, their involvement in the development of vitiligo remains controversial.

Objective

We evaluated the association between vitiligo and the CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants in a Mexican population.

Methods

A total of 116 vitiligo patients and 117 control subjects from northeast Mexico were included in the study and analyzed through PCR-RFLP to determine whether there is an association between vitiligo and CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants.

Results

No statistical difference was observed for both gene polymorphisms between vitiligo patients and controls (p > 0.05). Otherwise, vitiligo activity, family history of vitiligo, personal history of autoimmune diseases, or sex did not show any difference (p > 0.05).

Conclusion

As suggested by the analysis of a northeastern Mexican population, the CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants do not constitute a risk factor in the development of vitiligo.

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.

Association of CTLA-4 Gene Polymorphisms and Alopecia Areata: A Systematic Review and Meta-analysis

Objective: To provide evidence of the association between CLTA-4 gene polymorphisms and Alopecia Areata (AA). Methods: PubMed, EMBASE, Web of Science, Cochrane, Wanfang and CNKI databases were searched until April 30, 2021.The selection was completed according to the inclusion and exclusion criteria. The study quality assessment was based on Newcastle-Ottawa Scale. The assessment of the association was measured by ORs and 95%CIs. Results: Nine studies, containing 2858 AA cases and 5444 disease-free control subjects were included. For rs231775 polymorphism, no significant association with AA was found, which was A vs a, OR =1.02[0.81,1.30], P = 0.85; AA vs aa, OR =1.26[0.81,1.97], P = 0.31; Aa vs aa, OR =1.04[0.54,2.01], P = 0.91; AA + Aa vs aa, OR =1.04[0.71,1.53], P = 0.82; AA vs Aa + aa, OR =1.31[0.97,1.78], P = 0.08. For rs3087243 polymorphism, also no significant association was found, which was A vs a, OR =0.93[0.78,1.11]; P = 0.40, AA vs aa, OR =0.68[0.44,1.06]; P = 0.09; Aa vs aa, OR =0.87[0.45,1.68], P = 0.68; AA + Aa vs aa, OR =0.93[0.68,1.28], P = 0.66; AA vs Aa + aa, OR =0.78[0.34,1.81], P = 0.57. For rs231726 polymorphism, a significant correlation was found, which was A vs a, OR =0.76[0.70,0.82], P < 0.05. Conclusions: A significant correlation between CTLA-4 rs231726 polymorphism and AA susceptibility was found, but no significant association of CTLA-4 gene rs231775 and rs3087243 polymorphisms and AA susceptibility was found.

Effect of PTPN22, FAS/FASL, IL2RA and CTLA4 genetic polymorphisms on the risk of developing alopecia areata: A systematic review of the literature and meta-analysis

Objectives

Genetic association studies on alopecia areata (AA) performed in various populations have shown heterogeneous results. The aim of the current review was to synthesize the results of said studies to estimate the impact of FAS, FASL, PTPN22, CTLA4 and IL2RA gene polymorphisms on AA susceptibility.

Design

A systematic literature search was conducted in the Medline, Web of Science, Scopus, EMBASE and LILACS databases. Studies published up to June 2020 were included. The results available in the grey literature including the Open Grey and Google Scholar databases were also used. The texts of potentially related studies were screened by individual reviewers. Evidence of publication bias was assessed using the Newcastle-Ottawa scale and the quality of evidence was assessed using the GRADE system. The quantitative synthesis was performed using the fixed effect model.

Results

Out of 1784 articles, we identified 18 relevant articles for the qualitative synthesis and 16 for the quantitative synthesis. In a study of rs2476601 polymorphism of PTPN22 gene, including 1292 cases and 1832 controls, a correlation was found with the risk of developing AA in the allelic model (OR1.49 [95% C:1.13–1.95]), the heterozygous codominant (OR1.44 [95% CI:1:19–1.76]) and dominant model (OR1.43 [95% CI:1.18–1.73]). No association was found between the presence of FASL, PTPN22, CTLA and IL2RA gene polymorphisms with AA susceptibility.

Conclusions

The results suggest that the T allele of the single nucleoid polymorphism (SNP) rs2476601 in PTPN22 gene is a risk factor for developing alopecia areata. However, more robust studies defining the ethnic background of the population of origin are required, so that the risk identified in the present study can be validated. Additionally, a greater number of studies is necessary to evaluate the role of the FAS, FASL, PTPN22, CTLA4 and IL2RA genetic variants, given the heterogenous results found in the literature.