Abstract: Objective：To search the risk of reduced folate carrier gene（RFC1 A80G） polymorphism of parent and offspring with neural tube defects（NTDs）. The purpose is to provide the epidemiological evidence for finding genetic marker of NTDs. Methods: RFC1（A80G） genotype were detected using RFLP-PCR for blood DNA of the 104 triads with NTDs-affected child, and the 100 control families without child-affected birth defects. We investigated the association between the risk of NTDs and parental and offspring’s RFC1 genotype through a case?-parental control study and Family-based association test（FBAT）. Results: The parental heterozygosis GA/GA accounted for 36.36%; Twenty?-five percent of probability of offspring’s becoming homozygote GG which was associated with NTDs（P<0.05）， indicating that mother and father transmitted G allele to offspring by the probability. The G allele frequency of offspring with NTDs was higher than that of controls when compared to A allele（OR=1.56, 95% CI: 1.07-2.28）. There was evidence of association between G allele and the risk of parent having a child with NTDs in the case?-parental control study. However, there was no association between G allele and the risk of NTDs in the FBAT. Conclusions: Our findings indicated that there was no significant association between the risk of NTDs and offspring G allele in FBAT although there was potential association in case?-parental control study． However, the sample size of this study was limited, a larger samples of population?-based study is required to pursue the initial observation.

Key words: Congenital abnormalities, Neural tube defects, Membrane transport proteins, Reduced folate carrier gene, Family?-Based Association Test