[Autism Test] Can the FRAT Test Provide a Diagnosis?

Folate is a crucial nutrient that supports brain development, and most parents are well-aware of the importance of taking folic acid during pregnancy. However, recent research has revealed that even with an adequate dietary intake of folate, some children's brains may still be in a state of 'folate deficiency'. This occurs because the body produces autoantibodies against folate receptors, which block the transport of folate from the blood into the brain. This phenomenon is particularly common in children with autism spectrum disorder (ASD), and the Folate Receptor Autoantibody Test (FRAT) can be used to assess this specific issue.

Read on to learn more about the Folate Receptor Autoantibody Test, how to interpret the results, and the subsequent nutritional interventions you can consider supporting your child's development.

What is the relationship between folate autoantibodies and the autism spectrum?

The human brain has a 'blood-brain barrier' responsible for filtering which substances are allowed to enter the brain. To successfully cross this barrier and be utilised by nerve cells, folate must first attach (bind) to a protein called 'Folate Receptor Alpha' (FRα).

Folate receptor autoantibodies bind to FRα, blocking the entry to the ‘channel’ normally used by folate thereby preventing folate from entering the brain efficiently. When folate levels in the peripheral blood are normal but the concentration of 5‑methyltetrahydrofolate (5‑MTHF) in the cerebrospinal fluid is low along with neurological symptoms, the condition known as Cerebral Folate Deficiency (CFD) occurs.

A prolonged deficiency of folate in the brain can affect the synthesis of neurotransmitters, DNA methylation, and the normal development of nerve cells. These factors are closely linked to core symptoms of autism, such as delayed language development, social difficulties, and behavioural issues. Children with autism are about 19 times more likely to test positive for FRAAs than typically developing children without autistic siblings. A 2012 study published in Molecular Psychiatry found that folate receptor autoantibodies were detected in approximately 75.3% of children with autism.

What is the Folate Receptor Autoantibody (FRAT) Test?

The Folate Receptor Autoantibody Test (FRAT) is a simple blood test that requires only a small blood sample, that is sent to a laboratory for analysis. This makes the procedure minimally burdensome for children.

The test evaluates two types of autoantibodies against FRα in the blood:

Blocking Antibodies: These directly prevent folate from binding to the receptor.
Binding Antibodies: These attach to the receptor, potentially triggering an immune response or disrupting the normal function of the folate receptor.

Interpreting FRAT Results

The report provides separate titre values for both blocking and binding antibodies. Results are typically interpreted as follows:

Positive: One or both antibodies are detected.
Negative: Neither antibody is detected.

It is important to note that folate receptor autoantibody levels can fluctuate. They may be influenced by diet—especially dairy intake—as well as the individual’s immune status and, because of these, results may vary over time. If your FRAT result is negative but symptoms persist, please discuss with your doctor whether repeat testing is appropriate.

Who Should Consider the FRAT Test?

FRAT may be helpful for individuals with neurological, developmental, or psychiatric conditions potentially linked to cerebral folate deficiency or autism spectrum disorders. The following groups may consider testing:

Infants and young children with symptoms of Cerebral Folate Deficiency (CFD): including developmental delays, abnormal muscle tone, speech and language disorders, or spasms.
Children with Autism Spectrum Disorder (ASD) or developmental delays.
Pregnant women with relevant histories: such as previous miscarriages, autoimmune diseases, or a previous child diagnosed with autism.
Adults with neuropsychiatric or autoimmune conditions: including depression, schizophrenia, or bipolar disorder.
Individuals experiencing unexplained neurological symptoms.

OT&P Healthcare provides Functional Medicine services that take a whole-person approach to look at lifestyle, nutrition, and body systems to support personalised care. We also offer Autism Assessment services to help families better understand a child’s developmental needs and next-step support options. Please contact us for more information.

Does a positive FRAT result mean an autism spectrum diagnosis?

A positive FRAT result does not indicate an autism diagnosis. Instead, it serves as a clinical clue that the child’s brain may not be receiving an adequate supply of folate. With this information, doctors can conduct further assessments to determine whether intervention is required.

What can be done after a positive FRAT test result?

For children who test positive for folate receptor autoantibodies, doctors may prescribe folinic acid (Leucovorin) based on clinical judgement. Leucovorin is different from regular folic acid—it is a reduced, active form of folate that can bypass the FRα blocked by autoantibodies and enter the brain through alternative pathways. On 10 March 2026, the US FDA approved calcium folinate (leucovorin calcium) for treating adult and paediatric patients with cerebral folate deficiency caused by FOLR1 gene mutations.

A small randomised clinical trial published in 2018 reported that FRAA‑positive autistic children showed significant improvements in verbal communication after 12 weeks of high‑dose folinic acid, with the treatment generally well tolerated. In 2021, an analysis integrating multiple clinical datasets further supported the benefits of folinic acid for FRAA‑positive autistic children. In cases where autism and cerebral folate deficiency co‑occur, meta‑analysis has shown that leucovorin calcium can improve multiple symptoms, including:

Overall ASD symptoms
Irritability
Ataxia
Pyramidal signs
Movement disorders
Epilepsy

It is important to emphasise that folinic acid supplementation is not a cure for autism but a targeted treatment for cerebral folate deficiency. The dosage, treatment duration, and ongoing monitoring must be overseen by a doctor. Parents should never purchase these supplements on their own or adjust the dosage without medical supervision.

Conclusion

The folate receptor autoantibody test can offer families clues and hope for possible meaningful change for children on the autism spectrum. By identifying children who may have reduced folate in the brain, the test allows doctors to step in earlier and create personalised nutritional plans that may help improve symptoms and further developmental milestones.

If your child has been diagnosed with or is currently being assessed for Autism Spectrum Disorder, you may want to discuss with your doctor whether this test is suitable. Understanding your child’s biological needs early on can help you make the most informed and supportive decisions for their development.

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References

Frye, R.E., et al,. (2012). Cerebral folate receptor autoantibodies in autism spectrum disorder. Molecular Psychiatry, 18(3), pp.369–381. doi:https://doi.org/10.1038/mp.2011.175.
‌Rossignol, D.A. & Frye, R.E. (2021). Cerebral Folate Deficiency, Folate Receptor Alpha Autoantibodies and Leucovorin (Folinic Acid) Treatment in Autism Spectrum Disorders: A Systematic Review and Meta-Analysis. Journal of Personalized Medicine, 11(11), p.1141. doi:https://doi.org/10.3390/jpm11111141.
FRAT®, (n.d.) FAQs – Autism. Retrieved 11 March 2026 from https://www.fratnow.com/faqs.php
FRAT®, (n.d.) Blocking-Binding FRAAs. Retrieved 11 March 2026 from https://autism.fratnow.com/blog/blocking-binding-fraas/
‌National Organization for Rare Disorders, (2019) Cerebral Folate Deficiency. Retrieved 11 March 2026 from https://rarediseases.org/rare-diseases/cerebral-folate-deficiency/
Frye, R.E., et al,. (2016). Folinic acid improves verbal communication in children with autism and language impairment: a randomized double-blind placebo-controlled trial. Molecular Psychiatry, 23(2), pp.247–256. doi:https://doi.org/10.1038/mp.2016.168.
FDA, (2026) FDA Approves First Treatment for Patients with Cerebral Folate Transport Deficiency. Retrieved 11 March 2026 from https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-patients-cerebral-folate-transport-deficiency
Frye, R.E., et al (2020). Treatment of Folate Metabolism Abnormalities in Autism Spectrum Disorder. Seminars in Pediatric Neurology, 35, p.100835. doi:https://doi.org/10.1016/j.spen.2020.100835.