Rare diseases are a surprisingly common reality for Canadian families. Although each specific rare disease affects fewer than 1 in 2000 people, there are over 7000 known rare diseases. Added together, about 1 in 12 Canadians are affected by a rare disease (more than all cancers, cardiovascular disease or diagnosed diabetes), and two thirds of those diagnosed are children. However, achieving a diagnosis is too often a complex and frustrating journey, involving costly and often intense or invasive tests and procedures that provide no clear answers. Precision health, a groundbreaking approach that uses the power of genomics testing to understand each patient’s unique genetic code, could provide faster and more cost-effective diagnosis and treatment, in turn decreasing the burden on patients and families.
Because most rare diseases are of genetic origin and half occur with no family history, traditional diagnosis is challenging. There are four to five million variants in each person’s genetic code, some of which can cause genetic disorders. Identifying which variants are responsible for which disorders and whether a given variant is present in a patient’s DNA is critical for effective diagnosis. However, finding these variants through traditional genetic testing is extremely tedious, with a handful of suspected variants tested for one at a time. It can be as daunting as finding a needle in a haystack by pulling out individual pieces of straw.
In recent years, genomics and genome-based sequencing approaches have revolutionized rare disease diagnostics. By simultaneously sequencing the entire portion of a patient’s genome that codes for proteins (known as their exome), genomic-based testing is like searching the entire haystack at once.
While genomic sequencing is a powerful tool, accessing this testing requires that patients go through a qualified medical geneticist and meet specific criteria for testing. Evidence is accumulating, however, that earlier testing would be better for both patients and the healthcare system.
Genome Alberta is funding Care4Rare SOLVE, an initiative examining the economics of using genome-wide sequencing for patients with suspected rare diseases. Preliminary findings from the Care4Rare research team indicate that using genomic sequencing as the first test could reduce the time to diagnosis and the time the patient spends in the diagnostic pathway, in addition to reducing the number of diagnostic tests needed and overall testing costs.
Thanks to the development of next generation sequencing, which simultaneously sequences millions of DNA fragments in parallel, the cost of sequencing itself has become much more affordable. Today, whole genomes can be sequenced within hours, at a cost generally below $1,000 in a commercial setting. Furthermore, the use of genomic sequencing can lower the overall cost of testing by reducing the number of tests required to achieve a diagnosis. Without genomics, patients with a rare disease take an average of five to seven years to receive a diagnosis. With precision health approaches using genomic sequencing tools, the number of visits, tests and procedures can be reduced for patients and their health care providers, providing faster diagnosis and better outcomes at a lower cost. In one example, a five-year-old patient here in Alberta presenting with kidney abnormalities received a diagnosis within just 10 days.
“The impact of this work extends well beyond the value and impact of genome sequencing, to include the often-forgotten economic impact on families of patients,”
says Dr. Francois Bernier, MD, Professor Cumming School of Medicine, Departments of Pediatrics and Medical Genetics, Alberta Children’s Hospital Research Institute, University of Calgary.
According to the Canadian Organization for Rare Disorders (CORD), rare diseases cost the Canadian economy $111 billion annually in medical costs, nonmedical costs and productivity costs combined. A precision health approach could reduce these costs, but integrating new technologies into diagnostic standards takes time and investment. While genomic sequencing has proven to be cost-effective in other settings, more economic data are needed to understand whether the same benefits can be realized within our own healthcare system. Initiatives like Care4Rare SOLVE are helping provide needed evidence on the potential economic benefits of these technologies.
“People with rare disease often experience a lengthy diagnostic odyssey which can be frustrating and expensive from both a patient and system perspective,”
says Dr. Deborah Marshall, Scientific Director, Research and Partnership Evaluation and Impact, Alberta Children’s Hospital Research Institute.
“Our SOLVE research found that on average, people with a rare disease undergo more than 20 diagnostic tests before whole exome sequencing, and the average time between their first diagnostic test to receiving whole exome sequencing test results is approximately 3 years. By performing whole exome sequencing earlier in the diagnostic pathway, more people achieve a diagnosis faster and overall test costs are lower.”
Here in Alberta, approximately 25% of rare disease patients still experience an over five-year diagnosis delay. With wider adoption of genomic tools in the healthcare system, Albertans affected by a rare disease could experience a more streamlined path to diagnosis and treatment. As precision health technologies continue to advance, the future of effective, personalized healthcare grows brighter.
Learn more about the Care4Rare-SOLVE project here.