Association Study Of SNPs Of FcγRⅢA Gene And Environmental Factors With Systemic Lupus Erythematosus

Objective To explore frequencies and polymorphisms distribution of exon3,5 of FcγRIIIA gene, and analyse the susceptibility to systemic lupus erythematosus in indigenus Han Chinese of Anhui province, and to analyze the influences of interaction of many environmental factors and gene-environmental on systemic lupus erythematosus.Methods A total of 119 patients from 95 nuclear families, with SLE diagnosed by the ACR (American College of Rheumatology) 1997 criteria, were recruited. In addition, 316 family members of these patients were also genotyped. A family-based association test was used to explore the association between gene polymorphism and SLE. The method of PCR-based restriction fragment length polymorphism (RFLP) was applied to genotype single nucleotide polymorphism (SNP, rs428888, rs1042206, rs1042207, rs448740) of the FcγRIIIA gene .Results Among 119 SLE patients, the frequencies of FcγRIIIA-118Asn and FcγRIIIA-Aspalleles were 40.4% and 59.6% respectively.The frequency of FcγRIIIAAsn118Asn(C/C),Asn118Asp( C/T) and Asp118Asp(T/T) genotypes were 12.9 %,59.5%and 27.6%respectively; the frequencies of FcγRIIIA-239 Phe and FcγRIIIA 239Ser alleles were 11.9% and 88.1% respectively. Univariate (single-marker) family-based association tests (FBATs) demonstrated that variant alleles at a SNP, rs384288, in exon 3 of FcγRIIIA gene were significantly associated with genetic susceptibility to SLE in additive model (Z=2.271,P=0.023) and recessive model( Z=2.031 , P=0.042 ) .TDT(transmission/disequilibrium test) and SDT(sibship disequilibuium test) analysis showed an excess of the alleles of 118Asp from heterozygous parents to affected offspring (x~2=4.923, P=0.036) . The frequencies of FcγRIIIA Phe239Ser(C/T) and Ser239ser(C/C) genotypeswere 23.8% and 76.2%.But the TDT(transmission/disequilibrium test) and SDT(sibship disequilibuium test)...