For sporadic breast cancer, a de novo complete BRCA1 gene deletion, which includes Rho family GTPase 2 (RND2), BRCA1P1, BRCA1, and NBR2 complete genes, has been reported in a Spanish woman with early bilateral breast cancer, supporting the large genomic rearrangement screening of BRCA genes in young breast cancer patients without a family history, as well as in hereditary breast and ovarian cancer families previously tested negative for other variations (101). Here, RND2 is linked to breast cancer.