BRCAPRO and Myriad II are widely used models for predicting BRCA1/2 mutation 
probability before genetic testing. However, the accuracy of these models in 
Koreans is not known. This study was performed to evaluate the accuracy of the 
BRCAPRO and Myriad II models. Two hundred thirty-six women with breast cancer 
who underwent comprehensive BRCA1/2 genetic testing at our hospital between 2003 
and 2010 were included in this study. We evaluated the performance of each model 
by comparing the numbers of observed versus predicted mutation carriers. We 
calculated sensitivity, specificity, and predictive values at 10 % estimated 
probability. Forty-six individuals were identified to carry a deleterious BRCA 
mutation. The prevalence of BRCA mutation (19.5 %) was significantly higher than 
that predicted by BRCAPRO (9.0 %, p = 0.001) and Myriad (5.6 %, p < 0.001). In 
familial breast cancer patients, BRCA mutation rate (observed 22.7 %) was 
underestimated by both BRCAPRO (expected 11.4 %, p = 0.006) and Myriad II 
(expected 6.4 %, p < 0.001). Subgroup analyses showed that both models 
underestimated the risk of BRCA mutation in patients with a family history of 
breast cancer (probands' age at breast cancer diagnosis >50 years), with only 
one relative with breast cancer, and with non-familial early-onset breast cancer 
or bilateral breast cancer. Using a 10 % cut-off, the sensitivities were 47.8 % 
(BRCAPRO) and 50.0 % (Myriad), and positive predictive values were 44.9 % 
(BRCAPRO) and 43.4 % (Myriad). Both BRCAPRO and Myriad II underestimated the 
risk of BRCA1/2 mutation in Koreans. Our findings suggest that these models are 
less sensitive in Korean women, and therefore a new BRCA mutation prediction 
model based on Korean data is needed for proper genetic counseling.