The discovery of folate receptor alpha autoantibodies has provided novel insight into how impaired folate transport across the blood–brain barrier creates cerebral folate deficiency, leading to impaired myelination and behavioral deficits relevant to ASD, with recent studies confirming the efficacy of targeted metabolic intervention, and providing a non-toxic therapeutic with significant benefit to a large fraction of ASD children. Here, FOLR1 is linked to folate deficiency.