Treatment of Social and Language Deficits With Leucovorin for Young Children With Autism

This study tests leucovorin calcium treatment in young children with autism spectrum disorder (ASD) who have been confirmed to have folate receptor alpha autoantibodies (FRAA). FRAA are proteins that block folate from entering the brain — and this blockage may contribute to language and social difficulties in some children with ASD. Leucovorin, a special form of folate, can bypass this blockage and may help improve language and social communication. The trial is specifically for children 2.5 to 5.2 years old with ASD, confirmed FRAA-positive status, and significant language impairment. Unlike a similar trial (NCT04060017), this one requires confirmed FRAA status. Some children also undergo brain imaging with magnetoencephalography (MEG). Children with epilepsy, genetic syndromes, or metal implants that preclude MEG are excluded. You may be eligible if: - Your child is between 2 years 6 months and 5 years 2 months old - Your child has an ASD diagnosis (confirmed on ADOS-2 or ADI-R) - Your child has been tested and confirmed FRAA-positive - Your child has significant language impairment - Your child has early expressive language (voluntary babbling) You may NOT be eligible if: - Your child has not been confirmed as FRAA-positive - Your child has epilepsy, a genetic syndrome, or congenital brain abnormality - Your child was born before 34 weeks gestation - Your child has current or past liver or kidney disease - Your child has ferromagnetic implants, very large head circumference (above 60cm), or weighs above 185kg (for MEG sub-study) Talk to your doctor to see if this trial is right for you.