Rare Diagnostics
3-O-Methyldopa (3-OMD) — Dried Blood Spot Test
3-O-Methyldopa (3-OMD) — Dried Blood Spot Test
⚠️ Important — please read before ordering
The diagnostic services offered on this website are in vitro diagnostic tests intended to provide quantitative information on specific biochemical biomarkers. All results should be interpreted by a qualified healthcare professional — such as a physician, clinical geneticist, or metabolic specialist — in the context of the individual's clinical history and symptoms. These services are intended to support, not replace, medical consultation, diagnosis, or treatment. A positive, negative, or borderline result does not constitute a medical diagnosis. Rarediagnostics.eu is powered by Masdiag Sp. z o.o., a registered medical laboratory (podmiot leczniczy) operating under Polish and EU healthcare regulations.
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A targeted dried blood spot (DBS) test measuring 3-O-methyldopa (3-OMD), a metabolite of L-DOPA. It provides biochemical information to support the investigation of suspected aromatic L-amino acid decarboxylase (AADC) deficiency.
The standard home kit is for fingertip sampling only. For newborns and young infants, contact our laboratory before ordering to arrange appropriate collection.
What is the 3-OMD test?
3-O-methyldopa (3-OMD) is a metabolite formed during the metabolism of L-DOPA (levodopa) — a naturally occurring amino acid and the direct precursor to the neurotransmitter dopamine. When the enzyme responsible for converting L-DOPA into dopamine — aromatic L-amino acid decarboxylase (AADC) — is absent or severely deficient, L-DOPA accumulates and is instead converted to 3-OMD via an alternative metabolic pathway. This leads to significantly elevated levels of 3-OMD in the blood.
Elevated 3-OMD in DBS can support investigation of AADC deficiency. A specialist should interpret the result in the context of symptoms, medications and other test findings.
The test is performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) at our specialist laboratory in Warsaw.
What is AADC deficiency?
Aromatic L-amino acid decarboxylase (AADC) deficiency is an ultra-rare inherited neurometabolic disorder caused by mutations in the DDC gene. It affects the biosynthesis of monoamine neurotransmitters — dopamine, serotonin, adrenaline, and noradrenaline — which are essential for motor function, autonomic regulation, and neurodevelopment.
AADC deficiency typically presents in infancy with:
- Severe hypotonia (low muscle tone)
- Oculogyric crises — involuntary upward deviation of the eyes
- Developmental delay and intellectual disability
- Autonomic dysfunction (temperature instability, excessive sweating, nasal congestion)
- Movement disorders
AADC deficiency is frequently misdiagnosed or diagnosed with significant delay due to its rarity and the overlap of its symptoms with other neurological conditions. Elevated 3-OMD in a dried blood spot sample is a key biochemical indicator of AADC deficiency and should prompt further confirmatory investigation.
Interpretation and limitations
Tell the laboratory if the person being tested takes levodopa. Medication history is important when interpreting a 3-OMD result.
An elevated result can have other explanations. The treating specialist determines whether additional biochemical or genetic testing is needed.
Who is this test for?
- Infants or children with suspected AADC deficiency — hypotonia, oculogyric crises, developmental delay of unknown origin
- Clinicians and neurologists investigating neurotransmitter synthesis disorders
- Clinical geneticists investigating suspected AADC deficiency
- Researchers studying dopamine metabolism or rare neurometabolic conditions
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Price |
€60 |
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Sample type |
Dried blood spot (DBS) — capillary blood |
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Collection method |
Fingertip lancet (included in kit) |
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Analytes measured |
3-O-methyldopa (3-OMD) |
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Analytical method |
LC-MS/MS |
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Turnaround time |
10 business days from sample receipt |
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Kit delivery |
1–2 business days (EU) |
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Report format |
PDF with quantitative results, reference ranges and interpretation |
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Standard home kit suitable for |
Adults and children for whom fingertip collection is appropriate. For newborns and young infants, contact the laboratory before ordering. |
Frequently Asked Questions
What does an elevated 3-OMD result mean? ▼
Elevated 3-OMD can support suspicion of AADC deficiency. A specialist should review the result, medication history and any other relevant findings and decide which confirmatory tests are needed.
Can this test diagnose AADC deficiency on its own? ▼
The 3-OMD DBS test is a highly sensitive screening marker, but confirmation requires additional investigations including CSF neurotransmitter analysis and molecular genetic testing.
Can levodopa affect interpretation? ▼
Tell the laboratory if the person being tested takes levodopa, as this can affect interpretation. Discuss any treatment or dose decisions with the treating clinician.
Do I need a referral? ▼
No referral is required to order a test kit. Given the clinical complexity of AADC deficiency, we strongly recommend results are reviewed by a specialist.
How does it work?
Step 1 — Order your test kit
Order online. Your DBS collection kit will be shipped to your address anywhere in the European Union, typically within 1–2 business days.
Step 2 — Collect and dry your sample
The standard home collection kit is for fingertip sampling only. Use the enclosed lancet only for fingertip collection and follow the instructions included with your kit.
Newborns and young infants: Contact our laboratory before ordering to arrange an appropriate collection procedure. Do not use the enclosed lancet for heel-prick collection.
Allow the collection card to dry for at least 3 hours at room temperature, away from direct sunlight. Make sure it is completely dry before packing.
Step 3 — Register your sample
Before sending your sample to the laboratory, register it using the code supplied with your kit. This links the sample to the person being tested.
Register your sample online
Step 4 — Pack and send your sample
Place the fully dried card in the resealable bag with the desiccant, then put the bag in the enclosed return envelope. Follow the shipping instructions included with your kit to send the sample to our laboratory in Warsaw.
Step 5 — Receive your results
Results are delivered within 10 business days of sample receipt. You will receive a detailed laboratory report with quantitative results and interpretive comments.