The association study on the polymorphisms of estrogen receptor α and β genes and systemic lupus erythematosus in Chinese Han cohort of Yunnan Province

Objective To analyze the association of polymorphisms of estrogen receptor (ER) α and β genes with systemic lupus erythematosus (SLE) in Chinese Han cohort of Yunnan Province. Methods XbaI and PvuⅡ of ERα gene, RsaⅠ and AluⅠ of ERβ gene were typed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 697 SLE patients and 638 healthy controls. The frequency distribution of the alleles and genotypes were analyzed by Hardy-Weinberg equilibrium test and χ2 test. Results ① For ERα gene, the frequency of minor allele of Pvu Ⅱ C in SLE patients was significantly higher than healthy controls (χ2=15.427, P=0.001); the allele frequencies of XbaI in SLE patients showed no significant difference compared with healthy controls (P>0.05). The frequency of minor genotype of PvuⅡ CC in SLE patients was significantly higher than healthy controls (χ2=17.371, P=0.011). The frequency of two locus haplotype AATT in SLE patients was significantly lower than healthy controls (χ2=6.333, P=0.012); the frequency of the two locus haplotype AACC in SLE patients was significantly higher than healthy controls (χ2=7.771, P=0.038). ② For ERβ gene, the frequency of minor allele RsaI A in SLE patients was significantly lower than healthy controls (χ2=12.595, P=0.013); the allele frequencies of Alu Ⅰ in SLE patients showed no significant differences compared with the healthy controls (P>0.05). The frequency of minor genotype AA of RsaⅠ in SLE patients was significantly higher than healthy controls (χ2=41.456, P=0.000). The frequency of two locus haplotype AAGG in SLE patients was significantly higher than healthy controls (χ2=37.063, P=0.000). The frequency of the two locus haplotype AAGA in SLE patients was significantly lower than healthy controls(χ2=21.086, P=0.001). ③ PvuⅡ C was related with splenomegaly (χ2=4.212, P<0.05). The two locus haplotype AGTC of Xba Ⅰ and Pvu Ⅱ was related with edema (χ2=7.898, P<0.05). Conclusion There are associations between the polymorphisms of ERα and ERβ genes and SLE. The ERα and ERβ genes may be the susceptible genes for SLE in Yunnan Han Chinese Cohort. Key words: Lupus erythematosus, systemic; Estrogen receptor alpha; Estrogen receptor beta; Polymorphisms; Association study