It's possible for patients who have spent years searching for a diagnosis for their condition to get the answer from a network of cross-disciplinary experts -- the challenge now is how to make this model accessible for patients across the country, said researchers.
The first 1,519 consecutive patients referred to the (UDN) had a 40% acceptance rate for evaluation. By 20 months, a diagnosis was given to 35% of the 382 individuals who had received a complete assessment, reported Euan Ashley, MB, ChB, DPhil, of Stanford University in California, and colleagues.
Most of these diagnoses were made by exome or genome sequencing of the patient or a family member, according to the study published online in the. From the diagnoses, 80% of patients were led to changes in therapy, diagnostic testing, and/or variant-specific genetic counseling, Ashley said in an interview.
Additionally, the program defined 31 new syndromes from seeing these patients.
UDN was comprised of seven clinical sites, two sequencing cores, a coordinating center, a central biorepository, a metabolomics core, and a model organisms screening center during the study period (a 20-month window in 2015-2017), the researchers said. Greater investment has now grown the program to 12 clinical sites with an eye to cover more geographically diverse parts of the country.
"The aim of the is to provide wider access to cross-disciplinary expertise and to leverage specific advantages of the collaborative network, such as deep subspecialty expertise," the authors said. "Diagnostic evaluation is provided at no cost to patients."
In this study, NIH funding took on the average $15,116 cost for each patient to be evaluated. Before that, patients had spent close to $200,000 visiting doctors and undergoing repeat testing in their search for a diagnosis, the researchers noted.
Patients are invited to apply to the program if they have an undiagnosed condition even after a full clinical evaluation, Ashley and colleagues explained. Pediatric applicants were more likely to be accepted, and neurologic symptoms are the most common complaints.
"A critical aspect of broadening access is the need for qualified clinicians and genetic counselors. Another is the funding mechanism," the researchers stated.
"Although data from this study and from others suggest that money can be saved when the medical odyssey is cut short, attention should be focused on the aspects of the model that are most likely to be scalable, since infrastructure costs for such networks are not generally supported by healthcare systems," the team wrote.
Yet given the majority-white study population, the authors acknowledged that it was not clear how the program would fare with other patients.
The researchers found that one-third of accepted patients had previously received exome sequencing to no avail. Some got their diagnosis when UDN re-analyzed their data or had family members also undergo genome sequencing.
Patients still left without a diagnosis by the UDN are not forgotten, Ashley told ľֱ. "We reassure them of the fact that the team is still working on their cases. Every month there is new knowledge connecting new diseases. We get to revisit cases after a while, when new information comes to light."
Disclosures
Ashley reported co-founding Personalis and being an advisor for Sequence Bio.
Primary Source
New England Journal of Medicine
Splinter K, et al “Effect of genetic diagnosis on patients with previously undiagnosed disease” New Engl J Med 2018; DOI: 10.1056/NEJMoa1714458.