The first glimmer of hope of more tailored screening?
August 2009
A study published in Nature Genetics this week reported on a new
development in ovarian cancer genetics. They have discovered a
genetic variation, known as a Single Nucleotide Polymorphism ('SNP'
- known as a 'snip') which can increase the risk of ovarian cancer.
The scientists based at the Cancer Research UK Genetic Epidemiology
Unit, at the University of Cambridge and University College London,
have spent eight years looking at the DNA of thousands of women
with and without ovarian cancer. The area of risk DNA otherwise
known as a low penetrance gene is on chromosome 9. Louise Bayne CEO
of Ovacome said: "This is the first of the low penetrance ovarian
cancer genes - which slightly increase the risk of ovarian cancer -
to be identified and Ovacome welcomes this exciting advance."
What is a low penetrance gene?
Dr James Mackay, Consultant Clinical Genetic Oncologist, explains
that low penetrance genes slightly increase the risk of ovarian
cancer, whereas high penetrance genes such as BRCA1 and BRCA2
increase the risk much more. If you imagine a room with 1000 women
in it, and imagine they all had totally normal genes, over their
lifetimes, 10 of the women in the room would get ovarian cancer.
Now if you imagine that all the 1000 women had this new genetic
'SNP', then over a lifetime 14 of the women would get ovarian
cancer. If you imagine that they all had a BRCA gene mutation, 400
of them would get ovarian cancer. So you can see that although this
does increase the risk of ovarian cancer a little, it is a small
increase compared to some of the major genetic detections we
already know about. The really important thing about this study is
that, as more low penetrance ovarian cancer genes are identified, a
more tailored approach to screening could be provided.
