Genome project sheds light on rare diseases in Scotland
The detection and management in routine care of inherited rare and serious conditions can be improved by genome sequencing, according to a new study.
Until recently standard genetic testing focussed on small numbers of genes but as thousands more are implicated in diseases a new approach was needed.
The findings of the project, known as the Scottish Genomes Partnership (SGP), will be used to inform healthcare policy and funding decisions, experts say.
Whole genome sequencing involves reading the entire sequence of a person’s genes and identifying variants that differ from the normal pattern.
Scientists compare these against genes known to cause disease and then examine this shortlist of variants to identify which one might be the key to a person’s condition.
Rare conditions affect an estimated eight per cent of the population of Scotland with around 80 per cent of these conditions having a genetic cause.
There are more than 150,000 gene abnormalities known to cause developmental and learning difficulties and a host of conditions that impact long-term health, but many people are undiagnosed.
As members of the SGP, scientists from the University of Edinburgh sequenced 1,000 genomes from Scottish residents with rare conditions and their families where previous genetic testing had not identified a genetic cause.
The data were sent for processing and storage as part of the 100,000 Genomes Project – an initiative by Genomics England to sequence and study the role genes play in health and disease.
NHS Scotland genetic scientists and doctors then interpreted the analysed data and passed useful results to participants. A genetic diagnosis has been found in 23 per cent of participants so far.
The publication of the SGP results represents a landmark for application of genome technology to the healthcare of Scottish patients with rare genetic disorders. Continuously reducing costs of genome sequencing stands to increase future availability of genome-based testing for patients with rare diseases in Scotland.
The SGP involved the Universities of Aberdeen, Edinburgh, Glasgow, and Dundee, NHS Grampian, NHS Greater Glasgow and Clyde, NHS Lothian, NHS Tayside and Genomics England.
The findings have been published in the European Journal of Human Genetics and were funded by with funding from NHS Scotland, the Scottish Government and the Medical Research Council.
Having an undiagnosed genetic condition brings a huge amount of worry for those affected but it is our hope that diagnosis through genome sequencing can bring answers and improve the lives of patients and their families.
Many people with rare conditions face significant challenges in getting a diagnosis, with more than a third of people with a rare condition having to wait more than five years. This diagnostic odyssey can have a significant impact on the quality of life and wellbeing for a person with a rare condition and their family.
[Image credit: DamienGeso via Getty Images]