A type of vitamin B called folinic acid could improve the communication skills of children with autism, according to a study from Arkansas Children's Research Institute.

The randomized, placebo-controlled trial found that high prescription doses of folinic acid not only helped autistic children communicate better, but also identified specific biomarkers that could identify which children were most likely to respond to treatment.

Autistic children were randomized to receive either a placebo or high-dose folinic acid, which is a reduced form of folate.

"Improvement in verbal communication was significantly greater in participants receiving folinic acid as compared with those receiving the placebo," says lead author Richard Frye.

Up to 2 percent of American children are believed to experience symptoms of autism spectrum disorder (ASD). According to the Centers for Disease Control and Prevention, the current diagnosis rate is about 1 in 68 children, a tenfold increase from 40 years ago.

The main signs and symptoms of autism include difficulty in communication and interactions with other people, especially in social settings, and unbreakable routines or repetitive behaviors.

Currently, there are currently no approved treatments to treat the basic symptoms of the disorder.

"The only currently approved medications for autism are antipsychotic medications that address non-core symptoms and can lead to unwanted side effects," says John Slattery, a co-author of the study.

Previous research has linked folate to autism. Studies have found abnormalities in the metabolism of folate as well as genes involved in folate metabolism. Some studies have also shown that the offspring of women who took folate supplements before conception and during pregnancy had a lower risk of having a child with ASD.

About a decade ago researchers described a condition known as cerebral folate deficiency (CFD) in which the concentration of folate is below normal in the central nervous system but not in the blood.

Many children with CFD had ASD symptoms, and responded well to treatment with high-dose folinic acid.

The new study shows that children with high amounts of folate receptor autoantibodies had a more favorable response to the folinic acid treatment.

The study was published in the journal Molecular Psychiatry.

Another study, this one from the scientists at Boston Children's Hospital, found that half of autism cases are caused by a genetic disorder called TSC, which prevents cells from ridding the body of dead or dying mitochondria. There are already two classes of medicines to treat the defect — drugs known as mTOR inhibitors and the epilepsy drug carbamazepine.