Soon after scientists in 1994 identified the first genes linked to breast cancer, they discovered mutations among Ashkenazi Jews. But did this early success skew research into breast cancer?

The focus on the Ashkenazi has distracted scientists from finding mutations in other groups, some experts say. They suggest that scientists should concentrate on geographical ancestry rather than on ethnicity.

It's controlled by one company, and they set prices. Mary-Claire King, University of Washington

Aided in part by the relative ease of assembling Jewish study cohorts and DNA databases established for fighting Tay-Sachs disease, researchers identified three mutations in BRCA1 and BRCA2, which together account for 95% of BRCA-linked breast cancers in Ashkenazi women. Ashkenazi Jews are of Central and Eastern European descent and comprise about 90% of American Jews.

The three BRCA mutations account for only a fraction of Ashkenazi breast cancers, but they are the strongest results yet found in a single group. With tests to focus on the three mutations, screening in Jewish women has become inexpensive and widespread.

Although the mutations are more frequent among the Ashkenazi, they are not unique to that population. One of the mutations has been found in large numbers in Jewish women of, among others, Greek, Iranian and Moroccan descent, along with non-Jewish South Indian, Spanish Gypsy and Hispanic women. Another of the mutations is widely found in non-Jewish people from Central and Eastern Europe and Greece.

“[Ashkenazi] women are more closely monitored,” says Sheila Rothman, deputy director of Columbia University's Center for the Study of Society and Medicine. “But other women who may be at the same risk don't appear to have access to predictive testing.”

Other common mutations have also been found worldwide. But little of that research is conducted by US scientists, who tend to use categories such as 'white' and 'African-American' that are too broad to be meaningful.

Utah-based Myriad Genetics has also patented the BRCA genes and sells an Ashkenazi-specific test but offers no other ethnically tailored scans.

“Why don't they do Polish panels in the US? Because Myriad's interest is the full test,” says Canadian researcher Steven Narod, who helped identify BRCA1 and offers tests tailored to Polish, Dutch and French-Canadian women.

The monopoly also squeezes academics. Even at a discounted rate negotiated by the US National Institutes of Health, the BRCA screen costs $1,450.

“Is that fair? Of course not,” says Mary-Claire King, whose work paved the way for the BRCA identifications. “[But] it's controlled by one company, and they set prices.”

Myriad's claims are more limited in Europe (Nat. Med. 10, 882; 2004), allowing other screens to emerge. But in the US, given the non-Ashkenazi targets, King says, “the most clear and useful piece of information is whether a family has Ashkenazi Jewish ancestry.”