Women from high-risk families with mothers, sisters and aunts affected may want to know if they inherited a faulty gene.

The agency, they said, would "red-flag" the most high-risk, dysfunctional families and assign only the most experienced caseworkers to them.

With the gene now isolated, scientists can begin devising tests to screen women who come from high-risk families.

And for women in a high-risk family who do not themselves carry the mutated gene, she says, the "risk remains the same as everybody else's, one in eight."

We provide services and support to a group of high-risk families living in welfare hotels.

Examples of loci that have been identified in studies of high-risk families are discussed below and are summarized in Table 2.

The high-risk families come from (mostly female) children who carry a new causative mutation but are unaffected and transmit the dominant mutation to grandchildren.

The first women to benefit from screening will be those in high-risk families, in which several close relatives had breast cancer at a young age, before menopause.

Dr. Critchfield of Myriad Genetics said only 6 percent of the women who got the test came from such high-risk families.

For high-risk families (those with severely allergic parents or siblings), it's recommended pregnant women avoid cigarette smoking and prepare to breastfeed exclusively.