Zofia Miedzybrodzka, professor of medical genetics at the University of Aberdeen, and colleagues from the University of Edinburgh examined data from more than 2000 volunteers with three or more grandparents from Orkney. They found a variant of the BRCA1 gene present in one in 100 of those men and women. The research team believes the gene variant can be traced back to one of the founding members of Isle of Westray, Orkney, at least 250 years ago. Results are published in the European Journal of Human Genetics.
'Developing cancer is not solely down to carrying the BRCA1 variant alone,' said Professor Miedzybrodska who led the study. 'There are many risk factors, and some people with gene alterations will not get cancer. However, we know testing and the right follow-up can save lives.'
Professor Miedzybrodska is also director of the NHS North of Scotland Genetic Service based within NHS Grampian in Aberdeen, and has run the genetic clinic in Orkney for over 20 years. It was during this time that she and her team identified the same BRCA1 variant – p.Val1736Ala – in multiple women with breast and/or ovarian cancer who had parents or grandparents from Orkney. Authors of the paper proposed that women with two or more Orcadian grandparents should be offered testing, regardless of history of ovarian or breast cancer in their family.
'As it is hereditary, the gene variant can affect multiple members of families,' said Professor Miedzybrodska. 'Risk-reducing surgery, breast screening with MRI from age 30 and lifestyle advice can all improve health for women with the gene. Men do not need to take any particular action for themselves, but they can pass the gene onto female descendants.'
The team wanted to make a test available to all people with Westray grandparents who want to know if they have the gene variant.
'Many people who have the gene alteration are unaware of it. Not everyone wants to have a genetic test that looks into their future. In the long run we want to make a test available to those with Westray grandparents who want to know if they have the gene variant' added Professor Miedzybrodska.
Jim Wilson, professor of human genetics at the University of Edinburgh who was also involved in the study said: 'The fact that one in a hundred Orcadian women carry a high-risk variant for breast and ovarian cancer highlights the value of population studies such as Viking Genes, without which we would not know this.
'It is imperative that Scottish island populations are represented in research, to allow equitable delivery of genomic medicine across the country.'