A rapid immunoassay predicts BRCA1 and BRCA2 mutations in buccal cells.

We developed a rapid, non-invasive, and inexpensive, assay capable of identifying BRCA1 and BRCA2 (BRCA) mutations in buccal cells. To determine the predictive value of this immunoassay, a double blind study of 13 high risk individuals was conducted by two independent teams. As greater than 90% of BRCA mutations result in protein truncations, a diminished anti-carboxy immunoreactivity relative to anti-amino immunoreactivity was scored as predictive for mutation. Comparison to BRCA DNA analysis was undertaken. The positive and negative predictive values were 90% and 100% respectively (p<0.02), suggesting great promise as an inexpensive and rapid screen for BRCA mutations.