RFK Jr. has stated leucovorin will help « large numbers of children who suffer from autism. » Many experts are skeptical about that.
Last September, Health Secretary Robert F. Kennedy Jr. and President Donald Trump made a big announcement: The federal government had supposedly uncovered a clear link between autism and mothers taking acetaminophen (Tylenol) during their pregnancy. The proclamation was swiftly lambasted by scientists outside the administration, yet it’s only one facet of the Trump administration’s concerning new approach to autism.
That same day, RFK Jr. stated the Food and Drug Administration would soon approve a new treatment for autism, a form of folate (vitamin B9) known as leucovorin. As with the acetaminophen link, however, the evidence supporting the use of leucovorin for autism rests on shaky ground, to say the least. And many experts worry about what could happen to people with autism and their families if the drug starts to become widely taken.
“The idea of doing this for everyone—we’re going to see side effects, we’re going to see negative outcomes,” Audrey Brumback, a pediatric neurologist specializing in autism and other neurodevelopmental conditions at UT Health Austin, told Gizmodo.A shaky case
Leucovorin (folinic acid) is a form of the vitamin folate, also known as vitamin B9. Folate has many functions, from helping the body make red blood cells to supporting the healthy development of a fetus. The latter is why doctors now advise pregnant women to take folic acid (a synthetic form of folate) supplements, since low folate levels raise the risk of children being born with neural tube birth defects. Leucovorin has historically been used to counteract the toxic side effects of certain chemotherapy drugs. But it’s also effective at treating a rare condition known as cerebral folate deficiency, or CFD.
CFD is characterized by having low folate levels in the brain but normal levels in blood (this distinction also makes it harder to detect). The low brain levels can then lead to neurological symptoms like seizures and intellectual disability, as well as trouble with speech and coordination; these symptoms usually begin to appear around the age of two.
The condition is commonly caused by defective antibodies that attack a protein called folate receptor alpha (important for transporting folate across the blood-brain barrier) but can also be tied to rare inherited genetic mutations in the FOLR1 gene, which encodes folate receptor alpha. Leucovorin can be transported through a different delivery method than folate receptor alpha, however, meaning it can raise folate levels in the brains of people with CFD. The earlier children with CFD are treated with leucovorin, the greater the chance they can avoid the developmental delays it causes, though the therapy can still help older patients.
Some of the symptoms of CFD are similar to those found in severe cases of autism, and some research has suggested people with autism are more likely to have CFD or antibodies to folate receptor alpha. Based on this early research, some scientists are genuinely hopeful about the potential of leucovorin to help children with both autism and CFD.
During the September announcement, RFK Jr. claimed leucovorin was an exciting therapy that might benefit “large numbers of children” with autism. Marty Makary, current FDA commissioner, went further, stating that leucovorin could possibly help “hundreds of thousands of kids,” which would represent a substantial portion of U.S. children diagnosed with autism (a 2016 study estimated that at least 1.5 million children in the U.S. had diagnosed autism, though it’s a figure that’s certainly risen since). And in its own announcement, HHS stated that leucovorin would become the first “FDA-recognized therapeutic for children with cerebral folate deficiency and autistic symptoms.”
Yet the actual language of the FDA decision only extends the labeling of leucovorin to treat CFD, with barely a mention of autism.
