In women with a strong family history of breast cancer a negative BRCA test does not necessarily guarantee safety from breast cancer. These women are still at increased risk of developing the disease as per findings from the latest research. These women should start breast cancer screening at earlier age from 35 to 40 years.

Researchers explain that defects in the BRCA genes account for only around 5% of all diagnosed breast cancers in developed countries.

In this study published of the 277 women, 190 had breast cancer, 48 had ovarian cancer, and 33 had both. Six were free of the disease.

Among the 531 living female relatives who were tested for the genetic faults, almost half (49%) tested negative. Of these, 28 developed breast cancer and four developed ovarian cancer.

Among the 184 first-degree relatives testing negative, 4 different BRCA1 and 2 "phenocopies" were identified, accounting for around one in four test results.

A phenocopy is when a patient develops the condition that a particular gene predisposes them to, but they test negative for the inherited genetic fault. This is likely to be due to other genetic variants (modifier genes) that mimic the physiological changes produced by that specific gene fault.


Posted by: Jessica

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