The Story Behind the FRAT Test: Understanding Folate Receptor Antibody Testing in Autism Care
Diagnostic Innovation in autism care includes research into biological factors that may affect folate transport in the brain. The FRAT test, or Folate Receptor Antibody Test, is a blood test designed to detect folate receptor alpha autoantibodies (FRAAs). These antibodies are studied because they may interfere with the movement of folate into the brain.[1,2]

Diagnostic Innovation in autism care includes research into biological factors that may affect folate transport in the brain. The FRAT test, or Folate Receptor Antibody Test, is a blood test designed to detect folate receptor alpha autoantibodies (FRAAs). These antibodies are studied because they may interfere with the movement of folate into the brain.[1,2]
Research into FRAAs developed from work on cerebral folate deficiency (CFD), a condition involving reduced folate availability in the central nervous system. Researchers later investigated whether folate receptor autoantibodies could also occur in children with autism.[2,3]
How Did Folate Receptor Antibody Testing Develop?
Early research identified folate receptor autoantibodies in children with neurological and developmental conditions. A 2008 study reported an association between these antibodies and cerebral folate deficiency.[3]
Later research examined FRAAs in children with autism and reported an association between these antibodies and autism in some study groups.[4] Researchers also identified two antibody categories: blocking and binding folate receptor antibodies. These may interact with the folate receptor through different mechanisms.[5]
The FRAT Test is designed to detect both blocking and binding folate receptor autoantibodies.
What Does FRAT Testing Mean for Autism Care?
FRAT testing does not diagnose autism. A positive result indicates that folate receptor autoantibodies were detected; it does not establish the cause of autism or predict a child's developmental outcome.
Research has found FRAAs in some children with autism, but results have varied between studies. This means that test results need to be considered alongside the child's clinical history and other findings.
Research into folinic acid autism therapy has also produced findings that require further study. Some trials have reported improvements in communication or other measures in selected children, but folinic acid is not a universal treatment for autism.[2]
Book a FRAT IgG Test after discussing whether testing is appropriate with your healthcare professional.
Frequently Asked Questions
What is the FRAT test for autism?
FRAT is a blood test that detects folate receptor autoantibodies. It does not diagnose autism but may provide information about folate receptor autoimmunity.[1]
Does the FRAT test diagnose autism?
No. Autism requires a comprehensive clinical assessment. FRAT testing addresses folate receptor antibodies and should not be used as a stand-alone autism diagnostic test.
How does folate receptor antibody testing work?
A blood sample is tested for folate receptor autoantibodies. FRAT testing can identify blocking and binding antibody types.[1,5]
Who should get tested for folate receptor antibodies?
Testing should be considered on an individual basis by a qualified healthcare professional, particularly when clinical findings raise questions about folate transport or cerebral folate deficiency.
Is there a connection between folate and autism?
Research has identified folate pathway abnormalities and FRAAs in some children with autism. However, this does not establish that folate abnormalities cause autism.[2,4]
Is the FRAT test reliable?
FRAT is designed to detect folate receptor autoantibodies, but the clinical meaning of these findings in autism continues to be studied. Results should be interpreted alongside the child's clinical history.
How do I interpret a FRAT test?
A positive or negative result should be interpreted by a healthcare professional. The result alone cannot determine whether a child has autism or whether folinic acid treatment will be beneficial.
References
- FRAT® Folate Receptor Antibody Test.
- Cerebral folate deficiency, folate receptor alpha autoantibodies and leucovorin treatment in autism spectrum disorders: a systematic review and meta-analysis. J Pers Med. 2021
- Folate receptor autoimmunity and cerebral folate deficiency in low-functioning autism with neurological deficits. Neuropediatrics. 2008.
- Cerebral folate receptor autoantibodies in autism spectrum disorder. Mol Psychiatry. 2013.
- Blocking and binding folate receptor alpha autoantibodies identify novel autism spectrum disorder subgroups. J Autism Dev Disord. 2016.