A recent study has identified a gene variant that increases the risk of breast and ovarian cancer in people with Orkney heritage.

The research suggests that one in every 100 people with grandparents from Orkney carries a specific mutation of the BRCA1 gene, which is known to increase the risk of breast and ovarian cancer. Most of these individuals can trace their family ancestry back to the island of Westray. This is the first time a geographic ancestral link of this kind has been identified within the UK. The researchers also discovered the specific Orkney gene variant in smaller numbers in genetic testing across the UK and even in the US.

Previous research has found that women from certain ethnic backgrounds, such as Ashkenazi Jews, also have a high rate of a specific BRCA gene variant. Across the UK, about 1 in 1,000 people have a BRCA1 mutation, which can leave women at a higher risk of ovarian and breast cancer.

The BRCA genes are present in every person, both men and women, but when a fault occurs in one of them, it can result in DNA damage and lead to cells becoming cancerous. People with a genetic variant have a 50% chance of passing it on to their children.

The researchers identified a specific variant – BRCA1 V1736A – which is likely to have arisen in a founder individual from Westray at least 250 years ago. So far, 37 women of Orcadian heritage with the variant have been identified, some of whom have chosen to have risk-reducing surgery. There are also 20 people found to have the gene variant who don’t yet know they carry it.

The design of the study at the time meant information would not be disclosed. The team behind it has now asked the Research Ethics Committee for permission to contact the women identified to tell them they have the BRCA1 gene variant. The researchers believe that people with a shared ancestry around the world should be offered a targeted test for the variant. Currently, in Scotland, the test is available to those who know of a direct family connection to the gene or have a history of ovarian or breast cancer in their family.

Planning is underway for a small pilot trial that will offer to test to anyone living in Westray with a Westray-born grandparent, regardless of family history. If the pilot is successful, the long-term aim is to offer the test to everyone in Scotland with a Westray-born grandparent who wants it. The NHS Grampian genetics clinic is running a helpline for queries about the gene variant linked to breast and ovarian cancer for those who have grandparents from Orkney.

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  • Photo by Giulia Hetherington: instant images