FANCD2 associated with sporadic breast cancer risk.

Several components of the Fanconi anaemia (FA) family of proteins allow the formation of the DNA repair complex foci formed by proteins such as BRCA1/2 and RAD51. Because the genes that participate in the DNA repair pathway have been described as low-penetrance breast cancer susceptibility genes, we postulated that variants in FA genes could also be associated with sporadic breast cancer risk. We studied seven SNPs in FANCA, FANCL and FANCD2 in a total of 897 consecutive and non-related sporadic breast cancer cases and 1033 unaffected controls from the Spanish population. We observed a statistically significant association with sporadic breast cancer for the variant rs2272125 (L1366L) located on FANCD2 (OR per allele=1.35; 95% C.I. 1.09-1.67; P=0.005). Both haplotype and diplotype analyses confirmed this association, where one haplotype and pooled diplotypes carrying it were associated with more than 4-fold risk (P=0.007 and P=0.006, respectively). Screening for potential causal variants in FANCD2 was performed, detecting one in the putative promoter region, which is located in a phylogenetically conserved motif with consensus binding sites for some transcriptional factors, suggesting a functional implication. Our data indicate that a relationship between FANCD2 and sporadic breast cancer risk may exist.