About
FRAT testing measures folate receptor alpha autoantibodies, which may interfere with the body’s ability to transport folate across the blood–brain barrier.
This can contribute to a pattern sometimes referred to as cerebral folate deficiency, where folate levels in the bloodstream may appear sufficient, but delivery into the central nervous system is impaired.
At the London Clinic of Nutrition, we use FRAT testing as part of our functional medicine approach — looking beyond symptoms to identify potential underlying biochemical and immune drivers.
FRAT Testing
Supporting neurodevelopment through personalised, root-cause care.
The Folate Receptor Antibody Test (FRAT®) is a specialised blood test that helps us assess whether the immune system is producing antibodies that may interfere with folate delivery to the brain. Folate is essential for brain development, communication, behaviour and cognitive function — particularly during early childhood.
In some individuals, including a subset of children with autism spectrum disorder (ASD), these antibodies may reduce the amount of folate reaching the brain even when dietary intake and standard blood folate results appear normal.
Please note that FRAT testing is only available as part of our consultation package. We use results to help our practitioners understand your biochemistry more clearly, so we can create a safe, personalised plan.
Why folate matters in neurodevelopment
Folate plays a central role in many pathways that support healthy brain development and function, including:
Neurodevelopment and synapse formation
Neurotransmitter production
Methylation and detoxification pathways
DNA synthesis and repair
Immune and inflammatory regulation
When folate transport to the brain is compromised, children may experience challenges related to language development, learning, attention, behaviour, emotional regulation and cognition.
The role of folinic acid (leucovorin)
When FRAT antibodies are present, practitioners may consider the clinical relevance of folinic acid — also known as leucovorin — under appropriate medical supervision.
Folinic acid is an active, reduced form of folate that does not require conversion via the MTHFR pathway and may help bypass certain transport or metabolic limitations. In some research settings, leucovorin has been explored in children with cerebral folate deficiency and subsets of autism where folate receptor autoantibodies are present.
It’s important to note:
Folinic acid is different from folic acid.
It should only be used under professional guidance.
It is not appropriate for every patient.
At our clinic, decisions regarding folinic acid or any therapeutic intervention are made carefully, based on laboratory findings, symptom presentation, medical history and individual tolerance.
When FRAT testing may be worth considering
FRAT testing may be appropriate for individuals who present with neurological or developmental concerns, particularly when standard testing does not fully explain the clinical picture.
We may consider FRAT testing for:
Children diagnosed with autism spectrum disorder (ASD)
Children with speech delay or developmental regression
Individuals with attention, learning or behavioural differences
Patients with signs suggestive of cerebral folate deficiency
Families seeking a root-cause, integrative evaluation rather than symptom-based care alone
This test is often explored when families are trying to understand why certain therapies or interventions may not be producing the expected progress, particularly in complex conditions such as chronic fatigue syndrome.
Why folate can look “normal” but symptoms persist
Standard folate tests typically measure serum folate (and sometimes RBC folate). These markers can be useful, but they do not assess whether:
Folate is effectively crossing the blood–brain barrier
Immune-mediated antibodies are interfering with folate receptors
Folate is being properly utilised in methylation and neurotransmitter pathways
FRAT testing can provide deeper clarity when clinical suspicion remains despite “normal” routine labs.
What does the FRAT test measure?
FRAT testing measures two key types of folate receptor alpha autoantibodies:
Blocking antibodies
These may prevent folate from binding to its receptor, limiting transport into brain tissue.
Binding antibodies
These may interfere with receptor function or signalling, reducing the efficiency of folate delivery.
Identifying these antibodies can provide insight into potential biochemical contributors to neurological and developmental differences.
What does the test involve?
FRAT testing is a straightforward blood test.
It typically involves:
A simple blood draw
No fasting required, unless otherwise advised
Sample sent to a specialised reference laboratory
Detailed interpretation with your practitioner
Results are considered alongside your full clinical picture — including nutrition, gut health, immune status, genetics, environmental exposures and current therapies.
Please note that we can only arrange FRAT testing following an initial consultation with a practitioner.
How FRAT testing fits into an integrative care plan
In functional medicine, FRAT testing is not used in isolation. It forms part of a comprehensive, whole-child or whole-person approach that may include:
Personalised dietary strategies
Targeted supplementation (including consideration of folinic acid/leucovorin where clinically appropriate)
Immune and inflammation-supportive interventions
Gut health optimisation
Ongoing developmental and therapeutic collaboration
Our goal is never to “treat a lab result”, but to support optimal neurological function, resilience and developmental potential.
What FRAT results can — and cannot — tell us
FRAT testing may help:
✔ Identify an immune-mediated barrier to folate utilisation
✔ Clarify contributors to neurological or developmental challenges
✔ Support more personalised and informed care decisions
However, FRAT testing:
❌ Does not diagnose autism
❌ Is not a standalone explanation for all symptoms
❌ Should never replace comprehensive clinical evaluation
Results must always be interpreted thoughtfully within the broader context of each individual’s unique biology and story.
Partnering with families
We recognise that every child is different — and so is every family. Our mission in offering FRAT testing is to provide clarity, compassion and collaborative guidance, empowering families with meaningful information to support their child’s development.
If you would like to explore whether FRAT testing — and discussion of options such as folinic acid — may be appropriate, we welcome you to speak with our team.
