BRCA2 and breast carcinoma: In some ethnic groups NBS1 and RAD50 have been shown to be associated with breast cancer, eg, NBS1 657del5 increased breast cancer risk by 3-fold in Central and Eastern Europeans,86 I171V increased breast cancer risk among Poles,87 and RAD50 687delT was associated with a relative risk of 4.3 for breast cancer.88 However, no deleterious mutation in these 2 genes was found in 384 non-BRCA1/BRCA2 hereditary breast cancers in Chinese.89 Thus, there is no evidence to recommend RAD50 and NBS1 for genetic testing in China.