ABSTRACT
Objective To investigate the relationship between estrogen gene polymorphism and the incidence of melasma. Methods A total of 56 patients with chloasma blepharoplasty surgery (case group) and 39 healthy women with eyelid blepharoplasty (control group) were included in this study. The expression of estrogen receptor (ER) was detected by immunohistochemistry. The ERαgene PvuⅡand XbaⅠrestriction site polymorphisms and RsaⅠand AluⅠrestriction site polymorphism of ERβ gene were detected by PCR-restriction fragment length polymorphism (PCR-RFLP) analysis in two groups. The relationship between the incidence of ER and the score of melasma was analysed. Results Results of immunohistochemistry showed that there were positive expressions of ERα and ERβ in dermal fibroblasts and endothelial cells of case group, while there was weak expressions of ERα and ERβ in control group. Spearman correlation analysis showed that there was a positive correlation between ERα, ERβ and melasma score (rs=0.462 and 0.512, P<0.05). There was a significant difference in distribution of ERαgene XbaⅠgenotype between two groups (P<0.05). With xx genotype reference, the value of OR exposed to X allele (Xx+XX) was 2.23 (95%CI:1.41-3.89, P<0.05). There was a significant difference in ERβ gene AluⅠ genotypes between two groups (P<0.05 ). With aa genotype reference, the value of OR exposed to the A allele (AA+Aa) was 1.58 (95% CI: 1.21-4.29, P<0.05). There was a significant difference in RsaⅠgenotype distribution between two groups (P<0.05). With reference rr genotype, the value of OR exposed to R allele (RR+Rr) was 2.37 (95%CI:1.19-6.33, P<0.05). Conclusion The incidence of melasma is related with XbaⅠERαgenotype, ERβ gene AluⅠ, RsaⅠ genotype polymorphisms. The gene mutations increase the risk of incidence of melasma. Persons with Xx, Aa and RR genotypes are susceptible to melasma.