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Biopterin in Cerebrospinal Fluid (CSF)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of biopterin, a chemical involved in the production of certain neurotransmitters in your brain and spinal fluid.

Quick summary

["Biopterin levels may help diagnose or monitor conditions affecting brain chemistry."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47581-4
Short code
Biopterin CSF-sCnc
Synonyms
Biopterin CSF-sCnc
Category
coagulation
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85610
SNOMED
396252006
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms or a suspected condition linked to abnormal biopterin levels, such as certain neurological disorders or metabolic issues. It could also be part of a broader evaluation for inherited disorders affecting neurotransmitter production.

What to Expect Before the Test

No special preparation is typically required. You may be asked to fast or avoid certain medications, but your provider will clarify this. The test involves a simple lumbar puncture (spinal tap) where fluid is collected from your spinal canal.

What the Test Results Mean

Results are interpreted by your healthcare provider based on your clinical picture. Elevated or low levels may indicate specific metabolic or neurological conditions that need further evaluation.

Common Conditions Monitored

This test is often used to diagnose or monitor conditions like hyperphenylalaninemia, certain forms of intellectual disability, or other inherited disorders affecting neurotransmitter synthesis.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: csf

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Biopterin

Frequently asked questions

What causes abnormal biopterin levels in CSF?
Abnormal levels may be caused by inherited genetic mutations affecting biopterin metabolism, certain neurological disorders, or conditions that disrupt normal brain chemistry.
How long does it take to get results?
Results are typically available within a few days to a week, depending on lab processing times and your healthcare provider’s workflow.
Can I drink or eat before this test?
Follow your provider’s instructions, but generally, no special diet is required unless specified. Avoid alcohol or certain medications that may interfere with the test results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy