OBJECTIVETo test the association between XRCC1 gene polymorphisms and susceptibility of nasopharyngeal carcinoma in Cantonese nuclear families through a family-based association study.

METHODSA total of 2134 study subjects from 457 Cantonese nuclear families were recruited in the study. Each family had two parents and at least one offspring with nasopharyngeal carcinoma. Genotyping for three single nucleotide polymorphisms in XRCC1 gene, including rs1799782 (C > T), rs25489 (G > A) and rs25487 (G > A), were performed with PCR-RFLP assay. The genotype data were analyzed with family-based association test (FBAT) software to check linkage and association between the three genetic markers and susceptibility of nasopharyngeal carcinoma.

RESULTSFBAT analysis showed XRCC1 gene genotypes and haplotypes were not significantly associated with nasopharyngeal carcinoma in our study population (rs1799782: chi(2) = 1.006, P = 0.605; rs25489: chi(2) = 0.470, P = 0.790; rs25487: chi(2) = 2.563, P = 0.278; haplotype: chi(2) = 3.004, P = 0.557, global statistic). For rs25487, the G allele (major allele) showed increased transmission under dominant model (Z = 1.985, P = 0.047). Whereas the C allele (minor allele) exhibited reduced transmission under recessive model (Z = -1.985, P = 0.047). However, no increased/reduced transmission was observed under additive model and with global statistic.

CONCLUSIONThere is no evidence of an association between polymorphisms in XRCC1 gene and susceptibility of nasopharyngeal carcinoma in Cantonese nuclear families is observed in this study.