NEW YORK(GenomeWeb) – Illumina announced this week that it has begun shipping a new TruSight sequencing panel focused on genes associated with inherited heart conditions like sudden cardiac death.
The company told GenomeWeb that the new panel, TruSight Cardio, is the result of interest from researchers in the field looking for a way to cost-effectively interrogate a broader set of targets in a single test.
According to the company, efforts to discover the genetic causes of inherited heart conditions — much like the search for a genetic diagnosis in other diseases — have been stymied by the limitations of tests focused on single genes, or just a handful of targets.
If these more focused approaches fail to identify a plausible genetic cause, they can lead clinical researchers and their patients on an increasingly costly and time consuming odyssey of serial testing.
At the same time, expanding data has disfavored the concept that genes and symptoms or phenotypes connect in a one to one relationship; you can't rely on a patient's clinical features to determine what gene might be the root cause, raising demand for technologies that take a more agnostic approach up front.
"Existing gene panels for profiling genes related to inherited cardiac conditions tend to be smaller in size, leading to revalidation of bespoke panels, or having to send out tests when a particular set of genes are not available," Douglas McCannel, senior product manager for Illumina’s reproductive and genetic health business, told GenomeWeb in an email.
"We wanted to offer clinical research laboratories the flexibility to see a few genes, or as many genes as they needed depending on the question being asked, with quick turnaround time, a single workflow, and a low price point, all while avoiding unneeded re-validation," he added.
McCannel said that TruSight Cardio has been in development for more than a year. Stuart Cook of Imperial College London provided "medical input and technical guidance for the development of the product" and led testing of the panel at two of his labs, one inLondonand one inSingapore.
According to McCannel, Illumina also had five additional beta test sites, which all reported "consistent, highly accurate, and reproducible data," supporting the launch of the panel.
TruSight Cardio includes 174 genes known to be associated with 17 cardiac conditions, covering "all causal variants in these genes with a demonstrated link to inherited cardiac conditions.
"The panel includes both well-validated 'core' genes, as well as 'emerging' genes [for which] the relationship between gene and cardiac condition is not yet fully understood, but where peer-reviewed research has demonstrated a causal relationship between genes and conditions," McCannel wrote.
A research-use-only product, the kit allows for a 12-sample sequencing run on the MiSeq or the MiSeq Dx, he added.
Illumina hopes the new panel will be seen as an improvement over single-gene or handful-of-gene testing using Sanger sequencing, which has been a previous mainstay in the field.
At a cost of "approximately $1 per gene," according to the company, the price should be competitive, when one considers the potentially expanding costs and delays associated with serial testing of individual or handfuls of genes.
While even broader techniques like exome sequencing or other existing inherited disease gene sequencing panels are increasingly used, McCannel noted that TruSight Cardio strikes a middle path, improving the odds that researchers will identify a causal variant in patients with evidence of an inherited cardiac disorder, but with a very high depth and uniformity of coverage — 99.5 percent of targeted regions are covered at a minimum of 20X and a mean depth of coverage of 250X — and at a far lower price point than broader sequencing strategies.
With the new panel, Illumina continues to expand its portfolio of bespoke panels with lower cost and high coverage and uniformity, alongside its much broader sequencing products and capabilities.
In addition to TruSight Cardio, Illumina offers a cardiomyophathy-specific TruSight panel covering 46 genes, as well as a panel covering 101 genes linked to autism. The company's larger TruSight One panel covers 4,813 genes associated with a variety of known clinical phenotypes.
The firm also announced earlier this month a new TruSight HLA panel, which provides comprehensive coverage across 11 HLA loci.