Among patients with MS, variants in four genes increase the risk for developing drug-induced progressive multifocal leukoencephalopathy (PML) by 10 times, according to findings presented at the American Neurological Association Annual Meeting. Peggy Eis, PhD, and colleagues examined data from the FDA’s Adverse Event Reporting System and found that most of the drugs linked to PML were immunosuppressive disease-modifying therapies. They also determined that variants in four genes—C8B, FCN2, LY9, and STXBP2—increase the risk for developing PML by 10 times for patients who carry any one of these variants. “There are no treatments to cure PML, so prevention is the best defense, including knowing your genetic risk,” Dr. Eis said in a statement. “Even though the chance of developing PML is very low for some of these drugs, patients should still be screened given the ease and low cost of doing so relative to the avoidable potential consequences for those who do test positive.” She also noted that there are alternative treatment options for patients with MS who test positive for one of the genetic variants.
