Susceptibility Pathways in Fanconi's Anemia and Breast Cancer

Fanconi's anemia is a rare disorder that arises from defective repair of damaged DNA. Of the 13 Fanconi's anemia genes, 3 are breast-cancer–susceptibility genes. One is identical to BRCA2. Cells from patients with the D1 subtype of Fanconi's anemia and their family members carry biallelic mutations in BRCA2, and heterozygote members of kindreds with the D1 subtype have an increased risk of breast and ovarian cancer. Studies of a rare disorder can thus illuminate a common disorder.