Scientists partner with industry to develop new diagnostic test for inherited heart disease
7 Nov 2017
In January 2015, scientists at the MRC London Institute of Medical Sciences (LMS) published the results of a meticulous ‘proof of concept’ study looking for a mechanism underlying inherited heart disease. By carrying out a comprehensive analysis of the titin gene, the team identified specific defects which are important for causing dilated cardiomyopathy. This work led to collaboration with Illumina Incorporated to develop TruSight, a new diagnostic test for inherited cardiac conditions which was launched in May 2015.
Cardiomyopathy is a group of diseases that affect the heart muscle, and cause disease in around 1 in 500 people in the UK. The majority of cardiomyopathy is linked to inherited genetic conditions; therefore, identifying key cardiac genes along with their variations and defects has been a priority for researchers in this field.
Professor Stuart Cook at the MRC London Institute of Medical Sciences combines high resolution imaging of the human heart with genetic and genome analyses to understand cardiovascular biology and disease. In 2012 Professor Cook and a group of collaborators showed that defects in a gene called titin are the most common known genetic cause of dilated cardiomyopathy. The team studied a type of cardiomyopathy known as dilated cardiomyopathy to identify key genes that may be involved. Scientists have long suspected that a gene called titin may be implicated in cardiomyopathy, but this has been incompletely studied due to the technical challenges posed by the large size of the gene; titin is the largest human protein, coded for by the largest human gene, and this makes it extremely difficult to accurately sequence.
Nevertheless, the clinical significance of titin defects, and whether the identification of a titin defect changed a patient’s prognosis was still unknown. Even more problematic was the fact that three per cent of healthy normal individuals carry a titin defect, without any apparent consequences. For a genetic test to be clinically useful there should be little chance that the result could be a coincidental finding.
In 2015, Professor Cook and his team published the results of a comprehensive analysis of the titin gene, identifying which specific defects are important for causing dilated cardiomyopathy. This work provided evidence for a mechanism of the disease, and helped inform diagnostic criteria and management strategies for dilated cardiomyopathy patients who tested positive for these titin defects.
But the work didn’t stop there; a collaboration with Illumina Incorporated helped develop genes discovered by this research into a commercial cardiac gene panel. This panel, which was launched in May 2015, tests for 174 genes relating to 17 inherited cardiac conditions with a turn-around time of 24 hours and at a cost of £1 per gene. The NHS use of this test will ensure that patients who are at risk of sudden cardiac death receive appropriate interventions to prevent this. It will also mean that patients with a negative test result can potentially be discharged from follow up, freeing up NHS resources to target those patients who need it most.
In 2018, this work has attracted interest from the British Heart Foundation who have invested £2 million into a new study by Professor Cook. The study will look at the underlying causes of dilated cardiomyopathy using over 2,000 participants. It will investigate the link between genetic and environmental factors, developing further from a study which showed alcohol to increase the risk of the disease in people with faulty titin genes.
Award details: MC_U120085815