Understanding Your Medical Test: A Patient Guide to What It Is, How It Works, and What Results Mean
This test measures the level of 3-methylglutarate, an organic acid, in the fluid surrounding the brain and spinal cord to help diagnose certain metabolic disorders.
{"3-Methylglutarate is measured in cerebrospinal fluid (CSF) to detect metabolic disorders","Elevated levels may indicate problems with how the body breaks down certain proteins or fats","This test helps doctors diagnose rare genetic conditions affecting the brain and nervous system","The test requires a lumbar puncture (spinal tap) to collect CSF","Results help distinguish between different types of metabolic diseases"}
Key facts at a glance
- LOINC
- 72438-5
- Short code
- 3Methylglutarate CSF
- Synonyms
- 3Me-glutarate CSF-sCnc
- Category
- chemistry
- Sample
- csf
- Container
- Sterile polypropylene container for CSF collection
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Gas chromatography-mass spectrometry (GC-MS) or Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
- CPT
- 82491
- SNOMED
- 314432002
- Specimen volume
- 0.5-1.0 mL of cerebrospinal fluid
- Stability
- CSF should be frozen immediately at -20°C or -80°C if not processed within 30 minutes. Stable for several weeks at -80°C. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 200
- TAT
- 72–168 hours
- Order
- routine
What is this test, and what is it used to check or measure in my body?
The 3-Methylglutarate test measures the amount of a substance called 3-methylglutarate in your cerebrospinal fluid (CSF). CSF is the clear fluid that surrounds and protects your brain and spinal cord. 3-Methylglutarate is an organic acid produced naturally in small amounts when your body breaks down certain amino acids (the building blocks of proteins).
How is this test performed, and what can I expect during the procedure?
A healthcare provider collects CSF through a procedure called a lumbar puncture, also known as a spinal tap. During this procedure, a thin needle is inserted into the lower back to withdraw a small amount of fluid. The sample is then sent to a laboratory where specialists measure the level of 3-methylglutarate using specialized equipment.
Why might I need this test, and what symptoms or conditions could make my doctor recommend it?
Your doctor may order this test if they suspect you or your child has a metabolic disorder. Symptoms that might prompt this test include developmental delays, seizures, muscle weakness, unusual body odors, or episodes of illness that worsen during times of stress or fasting. This test helps doctors determine if there is a problem with how the body processes certain chemicals.
What do the results mean, and how will my healthcare provider explain them to me?
Normal results mean that 3-methylglutarate levels are within the expected range. Elevated levels may indicate certain metabolic disorders, such as glutaric acidemia type I, multiple carboxylase deficiency, or other conditions affecting how the body processes proteins. Your doctor will interpret these results along with other tests to make an accurate diagnosis.
Reference range
Reference range for 3-methylglutarate in CSF is typically <1.0 micromol/L (varies by laboratory method and reference population). Results should be interpreted in clinical context with corresponding plasma and urine organic acid profiles.N/A
No specific fasting required for CSF collection. Patient should be informed about the lumbar puncture procedure. For metabolic disease investigation, concurrent collection of plasma and urine samples may be recommended for comprehensive diagnostic evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The 3-Methylglutarate test is primarily used to help diagnose and monitor rare inherited metabolic disorders. Elevated levels in CSF can indicate problems with amino acid metabolism, particularly conditions affecting the breakdown of lysine and tryptophan. These disorders can cause neurological symptoms because the buildup of certain chemicals can be toxic to the brain. Early diagnosis is important because some of these conditions can be managed with special diets, supplements, or medications that help reduce the buildup of harmful substances.
Frequently asked questions
Is the lumbar puncture procedure painful?
How long does it take to get results?
Do I need to fast before this test?
Can this test diagnose all metabolic disorders?
Sources
- 1
- 2
- 3
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.
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