Kurian and her colleagues used two of the most widely used computer models, named BRCAPRO and Myriad II, to predict the presence of the mutations in 200 white women and 200 Asian-American women at cancer genetics clinics in four locations: Stanford, the University of California-San Francisco, Queen's Medical Center in Honolulu and the British Columbia Cancer Center in Vancouver. They sequenced the BRCA1 and BRCA2 genes of all of the study subjects and compared them to the models' predictions.
The researchers found that the models were highly accurate in predicting the presence of mutations in white women; one program identified 24 of the 25 women with BRCA1 or BRCA2 mutations and the other identified all 25. However, both programs performed much worse in predicting the 49 Asian women in the study sample with mutations. One program predicted that only 25 of the 49 women would carry mutations, while the other recommended testing of 26 women.
"It's clear that these models are far from foolproof," said Kurian, who is also a member of the Stanford Cancer Center. "These results emphasize the need for expert evaluation by a genetics professional to guide all clinical genetic testing."
Because the Asian and white women reported similar numbers of affected relatives on average, it's possible that fewer Asians with the mutations go on to develop cancer. In that case, the family history would be a less accurate way to determine the presence of the mutations. Kurian and her colleagues are collaborating with researchers in Hong Kong to investigate these and other alternatives.
The study results point out the need for further investigation into the genetic variability of different ethnic groups. In addition to previously identified, clinically important mutations of the genes, the researchers identified more "variants of unknown significance" in the BRCA1 and BRCA2 genes of Asian women than in white women.
Many of these vari
|Contact: Krista Conger|
Stanford University Medical Center