Teachable moment in classrooms:

  1. cellular basis of life chapter – concept of one gene, one protein, in this case, the MTHF transporter in the choroid plexus
  2. cellular basis of life chapter – concept of gene mutation leading to protein malfunction such as the MTHF transporter in the choroid plexus
  3. nervous system chapter – location and function of the choroid plexus
  4. nervous system chapter – structure and function of the blood-brain barrier

The news item:  Recently this news article appeared online:

FDA approves new use of synthetic vitamin B9 – but not for autism symptoms

The FDA announced a new approved use for the drug leucovorin, which Trump has touted as a treatment for autism. But the approval is for cerebral folate deficiency.

The article states that Leucovorin was approved to treat cerebral folate deficiency which appears at the frequency of 1 in 1 million people. However, doctors have also been using it to treat autism. The FDA approval does not indicate use for autism, because there is no sufficient data about it.

So, Why Do I Care??  While cerebral folate deficiency (CFD) is a very low frequency disorder, found in about 300-400 people in the US, it is important to search for a remedy, because what we learn from the CFD treatment might be useful in other nervous system disorders, such as autism.

Plain English, Please!!! First, let’s talk about how folate (also can be called folic acid) deficiency lowers the functioning of the brain. Folic acid (vitamin B9) absorption to methyl tetrahydro-folate (MTHF), and active transport through the choroid plexus moves MTHF into the cerebrospinal fluid (CSF). From the CSF neurons can import MTHF for the purpose of stimulating neurotransmitter (dopamine, serotonin) synthesis, helping to neutralize free radicals, and for proper regulation of gene expression for neuronal development and maturation (myelination). In disorders where the MTHF transporter is disabled because of a mutation, then MTHF is not available for the neurons, thus neurotransmitter levels become abnormal, neuronal connections form only poorly, and myelination is incomplete.

Second, let’s talk about how Leucovorin acts as a remedy for CFD. Leucovorin is a chemical form of folic acid that can efficiently cross the blood-brain barrier. With Leucovorin treatment the neurons can receive folate even when the CSF has little MTHF. Therefore, when the choroid plexus MTHF transport is disabled because of a mutation of the transporter, the transport of Leucovorin through the blood-brain barrier can satisfy the folate need of the neurons. It’s like when you want to let fresh air into the house you normally open a window. But when your window is stuck and doesn’t open, you can open the door and let fresh air into the house. Leucovorin allows the brain to access the folate using an alternative path.

Third, let’s talk about how Leucovorin might help people with autism. The disorder of autism is not linked to folate deficiency. However, in some select individuals there might be undiagnosed folate deficiency, and those individuals will benefit from Leucovorin. When you hear reports that Leucovorin “miraculously” helped the condition of an autistic child, that was probably because the undiagnosed folate deficiency in that child.  When you hear reports that Leucovorin did not help autistic children, that’s because those children did not have an undiagnosed folate deficiency.