The FRAT test — formally known as the Folate Receptor Antibody Test (FRAT) — is one of the most important yet underutilised diagnostic tools in paediatric neurology today. If your child has been showing signs of developmental regression, speech delay, autism spectrum disorder (ASD), or unexplained seizures, understanding what the FRAT test measures and what it can reveal could be genuinely life-changing.

This comprehensive guide explains the FRAT test in plain language — covering the symptoms that indicate a need for testing, the biological causes behind the condition it detects, how the test procedure works, and what treatment options are available once you have a result.

What Is the FRAT Test?

The FRAT test is a specialised blood test that detects Folate Receptor Autoantibodies (FRAAs) — abnormal immune proteins that attack the Folate Receptor Alpha (FRα) protein on the choroid plexus of the brain. This protein is responsible for transporting folate (Vitamin B9) from the bloodstream across the blood-brain barrier and into the cerebrospinal fluid (CSF).

When FRAAs block this receptor, folate cannot enter the brain adequately. The result is a neurological condition called Cerebral Folate Deficiency (CFD) — a state of severe folate depletion in the brain despite normal folate levels in the blood. Standard blood tests, including routine CBC and serum folate levels, do not detect CFD because the problem exists at the blood-brain barrier level, not in the blood itself.

Research published in peer-reviewed journals, including studies by Dr. V. T. Ramaekers and colleagues, has demonstrated that Folate Receptor Autoantibodies are present in 60–75% of children with autism spectrum disorder, making FRAT testing critically important for this population. You can read more about the science behind this on the official FRAT test research portal and through publications on PubMed.

Symptoms That May Indicate the Need for FRAT Testing

Because Cerebral Folate Deficiency develops gradually and its symptoms overlap with other neurodevelopmental disorders, it is frequently missed without targeted testing. The following symptoms — particularly when they appear together or follow a period of apparently normal development — are important clinical indicators that a FRAT test should be considered.

Neurodevelopmental Symptoms

Developmental regression: Loss of previously acquired milestones, including speech, motor skills, or social responsiveness — especially between ages 1 and 4
Speech and language delays: Absent or significantly delayed speech, echolalia, or regression of vocabulary
Autism spectrum disorder (ASD): Diagnosis of ASD, particularly with features of regression or treatment resistance
Intellectual disability: Cognitive delays without a clear genetic or structural explanation
Attention and hyperactivity issues: Features overlapping with ADHD that have not responded to standard interventions

Neurological Symptoms

Seizures: Infantile spasms, myoclonic seizures, or epilepsy that is difficult to control with standard anticonvulsant medications
Hypotonia: Unusual low muscle tone, particularly in infants
Ataxia: Problems with coordination, balance, or gait in older children
Pyramidal signs: Spasticity, hyperreflexia, or abnormal neurological examination findings

Behavioural and Psychiatric Symptoms

Irritability or agitation: Persistent behavioural disturbance that doesn’t respond to behavioural interventions
Sleep disturbances: Chronic difficulty sleeping, waking frequently, or irregular sleep patterns
Sensory processing difficulties: Heightened or reduced sensitivity to light, sound, texture, or touch

If your child or a family member is experiencing several of these symptoms, we recommend speaking to a paediatric neurologist and requesting a FRAT test. Altus Lab Chandigarh provides FRAT testing with free home blood collection across Chandigarh, Mohali, and Panchkula, and pan-India courier kit services.

Causes of Folate Receptor Autoantibody Positivity

Understanding why some individuals develop FRAAs while others do not is an active area of ongoing research. However, several causal and contributing factors have been identified.

Immune System Dysregulation

The primary cause of FRAT positivity is an autoimmune response in which the body’s immune system mistakenly produces antibodies against the Folate Receptor Alpha protein. This is similar to other autoimmune conditions where the body attacks its own tissues. The exact trigger for this immune dysregulation is not fully understood, but it is thought to involve a combination of genetic susceptibility and environmental factors.

Dietary Folate Sources and Cow’s Milk Sensitivity

Research has suggested that in some children, the folate receptor protein in cow’s milk (which is structurally similar to human FRα) may trigger cross-reactive antibody production. This is why some children with FRAT positivity show improvement when cow’s milk and dairy products are eliminated from their diet. This finding was highlighted in studies led by researchers at the University of Maastricht, Netherlands, and has been corroborated by multiple subsequent research groups.

Genetic Factors

Certain genetic variants affecting folate metabolism — such as mutations in the MTHFR gene — may increase susceptibility to both folate deficiency and autoimmune responses. MTHFR mutations are particularly common in the Indian population, making FRAT testing especially relevant for Indian children showing neurodevelopmental concerns.

Environmental and Nutritional Factors

Nutritional deficiencies during pregnancy, inadequate folic acid supplementation in the periconceptional period, and environmental exposures may also contribute. This is one of the reasons why the FRAT test during pregnancy is now increasingly recommended by maternal-foetal medicine specialists.

How the FRAT Test Procedure Works

The FRAT test procedure is straightforward and non-invasive beyond a standard blood draw. Here is what to expect at every stage.

Step 1: Pre-Test Preparation

Before the test, patients are advised to:

Avoid folic acid supplements for at least 3–4 days before the sample is drawn, as high circulating folate can interfere with antibody detection
Avoid cow’s milk and dairy products for 3–4 days before testing, as milk folate-binding proteins can neutralise FRAAs in the sample and produce a false-negative result
Consult the treating neurologist before stopping any prescribed medications
Maintain overnight fasting if the lab requires it (confirm with your specific laboratory)

Step 2: Blood Sample Collection

A simple venous blood sample (typically 5–10 ml) is drawn into a plain or gel separator tube. At Altus Lab Chandigarh, our trained phlebotomists perform free home blood collection at your convenience. For patients elsewhere in India, we provide a FRAT Test Kit for pan-India sample collection — a temperature-controlled courier kit that ensures sample integrity during transport.

Step 3: Laboratory Analysis

The serum sample is analysed using a specialised ELISA (Enzyme-Linked Immunosorbent Assay) that detects and quantifies both blocking and binding Folate Receptor Autoantibodies. This test measures:

Blocking antibodies: Those that physically prevent folate from binding to the receptor
Binding antibodies: Those that attach to the receptor without necessarily blocking it, but which may still impair its function

Step 4: Report and Interpretation

Results are typically reported within 48–72 hours of sample receipt at the processing lab. Reports include the antibody titre levels (both blocking and binding), with reference ranges and clinical interpretation notes. Altus Lab reports are accepted by paediatric neurologists at PGIMER Chandigarh, Fortis Mohali, and Max Hospital.

FRAT Test Results: Understanding What They Mean

A positive FRAT test — meaning FRAAs are detected above the threshold level — confirms that Folate Receptor Autoimmunity is present and that the individual likely has or is at risk of developing Cerebral Folate Deficiency. If you have recently received a positive result, our detailed guide on what a positive FRAT test means and what to do next provides a clear step-by-step action plan.

A negative result does not completely rule out CFD, as a small percentage of cases may involve non-antibody-mediated folate transport defects. If clinical suspicion remains high despite a negative FRAT, a lumbar puncture for CSF 5-MTHF measurement may be considered by the treating neurologist.

Treatment Options After a Positive FRAT Test

The good news about a FRAT-positive diagnosis is that it is treatable. The primary treatment for Folate Receptor Autoimmunity-mediated Cerebral Folate Deficiency is folinic acid (leucovorin), which bypasses the blocked folate receptor pathway and restores folate levels in the brain.

Folinic Acid (Leucovorin) Supplementation

Folinic acid is the reduced, biologically active form of folate. Unlike regular folic acid, it does not require the FOLR1 receptor to enter the brain — it can cross the blood-brain barrier through alternative transport mechanisms. High-dose folinic acid supplementation (typically 0.5–1 mg/kg per day, adjusted by the treating neurologist) has been shown in multiple clinical studies to produce significant improvements in:

Communication and language development
Social engagement and eye contact
Seizure frequency and severity
Motor coordination
Behavioural and sleep patterns

Leucovorin calcium (the pharmaceutical name for folinic acid) is available in India by prescription and is manufactured by several Indian pharmaceutical companies. Treatment is typically long-term and requires regular monitoring of folate levels and clinical response.

Cow’s Milk-Free Diet

For patients in whom cow’s milk sensitivity is a contributing factor, elimination of cow’s milk and all dairy products from the diet may help reduce the production of new FRAAs over time. This dietary change is often recommended alongside folinic acid supplementation and is typically maintained for at least 3–6 months before reassessment.

Intravenous Immunoglobulin (IVIG) Therapy

In some cases with very high antibody titres or treatment-resistant presentations, IVIG therapy may be considered by the treating immunologist or neurologist. IVIG helps reduce autoantibody levels by modulating the immune response. This is typically used as an adjunct to folinic acid therapy rather than as a standalone treatment.

Complementary Therapies

FRAT-positive children continue to benefit from speech therapy, occupational therapy, applied behaviour analysis (ABA), and other evidence-based neurodevelopmental interventions. Folinic acid treatment creates the biological conditions for the brain to respond better to these therapies — many families report accelerated progress in therapy sessions after beginning leucovorin treatment.

Who Performs the FRAT Test in India?

The FRAT test requires specialist processing and is not available through routine diagnostic chains. Altus Lab Chandigarh is a leading provider of FRAT/FOLR1 Antibody testing in India, operating under the oversight of an Ex-PGIMER Chandigarh doctor with over 13 years of specialist diagnostic experience.

We offer:

Free home blood collection in Chandigarh, Mohali, and Panchkula
Pan-India FRAT Test Kit service via temperature-controlled courier
Reports accepted at PGIMER, Fortis, and Max Hospital
Specialist report interpretation support

To book your FRAT test or learn more, visit our FRAT / FOLR1 Antibody Test page or contact our team directly. You may also find it useful to read our guide for Indian parents navigating the FRAT test for the first time.

Frequently Asked Questions About the FRAT Test

Is the FRAT test covered by health insurance in India?

Currently, the FRAT test is not covered under standard health insurance policies in India as it is classified as a specialised/advanced diagnostic test. However, costs may be partially reimbursable under corporate wellness plans or international insurance policies. We recommend checking directly with your insurer.

How long does it take to get FRAT test results?

At Altus Lab Chandigarh, reports are typically delivered within 48 hours of sample receipt. For pan-India samples sent via courier, the total turnaround from kit dispatch to report delivery is approximately 7–10 working days.

At what age should children be tested?

The FRAT test can be performed at any age, from infancy onwards. Earlier testing generally allows for earlier treatment, which tends to produce better outcomes. Children as young as 6 months of age have been tested when clinical signs warrant it. For guidance on which children should be prioritised for testing, see our guide on who should take a FRAT test.

Can adults be FRAT-positive?

Yes. While the majority of FRAT testing focuses on children with neurodevelopmental disorders, Folate Receptor Autoimmunity can affect adults as well. In adults, it has been associated with schizophrenia, treatment-resistant depression, and multiple sclerosis. FRAT testing in adult populations is an emerging area of clinical research.

FRAT Test Explained: Symptoms, Causes, Procedure & Treatment Options