Genetic test aids risk detection for progressive multifocal leukoencephalopathy
Use of a genetic risk test for patients considering immunosuppressive therapies associated with development of progressive multifocal leukoencephalopathy may help reduce incidence of disease, researchers reported in Frontiers in Neurology.
Progressive multifocal leukoencephalopathy (PML) is a rare and often lethal brain disorder caused by the common, often benign polyomavirus 2, which is also known as JC virus, Eli Hatchwell, MD, PhD, co-founder and chief scientific officer at Population Bio Inc., and colleagues wrote.
“There are lots of conditions and drug treatments that increase people’s risk of PML, which is normally a very rare condition in the general population,” Hatchwell told Healio.
Hatchwell and colleagues theorized that patients may have a genetic susceptibility from the presence of harmful variants in immune-relevant genes. In a previous study, they discovered 19 candidate PML risk variants and validated four of them in population and matched controls.
“Patients with MS, and possibly other conditions, who are about to be started on a drug that is on the list of drugs that can cause PML would benefit from having a test to check for the variants that we have identified,” Hatchwell said.
According to the study, patients with any of the four variants identified are at high risk for PML (OR = 8.7; 95% CI, 3.7-20.6), with measures of clinical validity and utility comparing favorably to other genetic risk tests, such as those for breast cancer screening.
“If [a patient tests] positive for any of those variants, then due consideration would have to be given to either changing their planned therapy or being very cautious about how that therapy is implemented with very close clinical monitoring for any signs of PML,” Hatchwell said.
“There are very, very few specific tests that are based on a person’s genome, and this is one of those,” Hatchwell added. “We would like to think of it as an example of precision medicine and how, in the future, the more we know about a patient’s genome, the more we can tailor their treatments.”
The researchers concluded in the study, that “simple, low-cost genetic screening in patients considering drugs with known or suspected PML risk will prevent future cases.”