A New Breast Cancer Risk Gene

In the latest Nature Genetics, investigators from the Institute of Cancer Research in UK are describing a gene that might be responsible for the increased risk of developing breast cancer in women:

Scientists from The Institute of Cancer Research studied the BRIP1 gene in 1212 women with breast cancer who had a family history of the disease that was not due to the known breast cancer genes, BRCA1 or BRCA2. They compared these women to 2081 healthy people. They found nine BRIP1 faults (mutations) in the breast cancer patients but only two in the healthy individuals. This indicates that the gene is linked to breast cancer more often than would be expected by chance.
The team worked out that carrying a faulty version of BRIP1 doubled a women’s risk of the disease — taking their risk by the age of 70 from one in twelve to around one in six…
Inherited genetic faults are estimated to account for up to 25 per cent of familial breast cancer cases. Some of these damaged genes are well known, such as BRCA1 or BRCA2, but the majority of them are as yet unidentified. Scientists decided to look at faults in the BRIP1 gene because it interacts with the known cancer causing gene, BRCA1.
Having two faulty copies of the BRIP1 gene is extremely rare and this double genetic fault is a cause of Fanconi anemia — a childhood disorder that leads to bone marrow failure and leukaemia. This study looked at women who carry just one faulty copy of the BRIP1 gene who, although they are at an increased risk of breast cancer, are otherwise healthy.
BRIP1, like BRCA1 and BRCA2 is a DNA-repair gene, so women with a faulty version of this gene cannot repair damaged DNA correctly. Individuals with faulty DNA-repair genes have an increased risk of cancer because their healthy cells are more likely to accumulate genetic damage that can trigger the cell to replicate uncontrollably — causing cancer.

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