Folic acid as an adjunct in the treatment of children with the autism fragile-X syndrome (AFRAX).

Four boys with the combination of infantile autism and the fragile-X syndrome were given oral folic acid and placebo, according to a double-blind crossover design. One boy's behaviour appeared to improve on folic acid, but another boy did not seem to be affected at all. For the remaining two boys the results were equivocal. Further study of folic acid in the treatment of autistic boys with the fragile-X syndrome is warranted.