FDA Approves Rare Brain Disorder Treatment After Review

Science won a quiet victory this week when the FDA stuck to evidence over hype in approving a treatment for an ultra-rare genetic condition.

The Food and Drug Administration approved leucovorin, a synthetic form of vitamin B9, specifically for cerebral folate deficiency on Tuesday. This rare genetic condition, caused by a mutation in the FOLR1 gene, prevents the brain from getting enough folate and affects fewer than one in a million people.

The approval matters because it brings clarity. Last September, FDA chief Marty Makary suggested the drug would be made available for autism treatment, sparking hope among families and a 71 percent surge in off-label prescriptions for children. After a thorough scientific review, the agency determined there simply wasn't enough data to support that use.

"Autism is not caused by a folate deficiency," says David Mandell, a professor of psychiatry at the University of Pennsylvania who studies autism. The data suggesting otherwise are outdated and weak, he explains.

Cerebral folate deficiency can produce symptoms similar to autism, like communication issues. But autism is a separate, broad diagnosis that researchers believe has no single cause. The FOLR1 gene has never been linked to autism.

Helen Tager-Flusberg, a psychologist and autism researcher at Boston University, welcomed the FDA's clear stance. "There is a strong rationale for prescribing leucovorin for this specific condition," she says, noting it's a very different neurological disorder from autism.

The Bright Side

The decision shows that scientific review processes can work even under political pressure. The FDA, despite falling under the oversight of officials who had promoted the drug for autism, followed the evidence and approved it only for the condition it actually treats.

Families affected by cerebral folate deficiency now have an FDA-approved treatment option for their loved ones. Leucovorin, typically used to manage chemotherapy side effects in cancer patients, offers real hope for people with this specific genetic condition.

The true prevalence of cerebral folate deficiency remains unknown, but researchers can now study the treatment's effects more systematically with FDA approval in place.

Mandell acknowledges the challenge ahead in addressing the off-label use spike, but the FDA's clear decision gives doctors and families solid ground to stand on. When science leads the way, everyone benefits from treatments that actually work for the conditions they're meant to address.