BETHESDA, Md-Scientists from the National Cancer Institute have
found a specific mutation, 185delAG, in the breast cancer 1 gene
(BRCA1) in almost 1% of DNA samples from a study group of Eastern
European (Ashkenazi) Jews. This is the first time that scientists
have been able to show that the gene mutation is present at measurable
levels not only in high-risk families but also in a specific group
of the general population.
At a press conference, Donna Shalala, secretary of the US Department
of Health and Human Services, said that "this exciting finding
should allow us to move rapidly toward our goal of identifying
high-risk women and helping them to prevent breast cancer before
it strikes."
The study, an international collaboration between the National
Center for Human Genome Research (NCHGR), the NCI, the Sarett
Institute (Jerusalem), and the University of California, San Diego,
involved 858 unrelated Ashkenazi Jews from the United States and
Israel whose family or personal cancer histories were not known.
Eight (1%) of the individuals tested were found to have the 185delAG
mutation. This rate of alteration in the BRCA1 gene is three times
higher than all BRCA1 alterations combined in the general population.
Scientists did not find the alteration in 815 other samples from
individuals not selected for ethnic origins.
Dr. Jeffery Struewing, lead author of the report (Nature Genetics,
October, 1995), cautioned that the results were too preliminary
to recommend immediate BRCA1 testing for the nation's 5.5 million
Ashkenazi Jews. However, NIH has announced plans to launch a series
of clinical studies to evaluate cancer risk in Ashkenazi Jews
bearing the mutation.