Understanding Your Laboratory Test: Purpose, Procedure, and What the Results Mean for Your Health

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

This test measures 2-methylcitrate levels in dried blood spot samples to screen for rare metabolic disorders.

Quick summary

{"2-Methylcitrate is a biomarker for certain inherited metabolic disorders","The test is commonly used in newborn screening programs","Abnormal results may indicate conditions like methylmalonic acidemia or propionic acidemia","Early detection allows for prompt treatment and better outcomes","The test uses a small blood sample collected from a baby's heel"}

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

Key facts at a glance

LOINC: 82386-4
Short code: 2-MC
Synonyms: 2Me-citrate DBS-sCnc
Category: chemistry
Sample: serum
Container: Dried Blood Spot (DBS) card or serum separator tube (SST) for venous collection
Units: N/A
Ref low: 0
Ref high: 1.5
Critical range: — – 5 N/A
Fasting: false
Population: adult
Sex: all
Age range: 0–30 years
Method: Tandem Mass Spectrometry (LC-MS/MS)
CPT: 82017
SNOMED: 122465009
Specimen volume: DBS: One complete spot (approximately 100 μL blood) or serum: 0.5-1.0 mL
Stability: DBS: Room temperature stable for several weeks; Serum: 2-8°C for 7 days, -20°C for longer storage
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 24–72 hours
Order: routine

The 2-methylcitrate test measures the amount of 2-methylcitrate in a dried blood spot (DBS) sample. 2-Methylcitrate is a compound that builds up in the blood when the body cannot properly break down certain proteins and fats. This test is primarily used as part of newborn screening programs to detect rare metabolic disorders early in life.

How is this test performed, and what should I expect during the procedure?

A small blood sample is collected from a baby's heel onto a special filter paper card. This is typically done within 24-72 hours after birth as part of routine newborn screening. The sample is then sent to a laboratory where it is analyzed for 2-methylcitrate levels and other metabolic markers.

What do the results mean, and how will my doctor use them to guide my care?

Normal 2-methylcitrate levels indicate that the baby's metabolism is working properly. Elevated levels suggest that the body is having difficulty breaking down certain amino acids (isoleucine, valine, methionine, and threonine) and odd-chain fatty acids. This can indicate conditions such as methylmalonic acidemia (MMA) or propionic acidemia (PA).

Reference range

Reference range varies by laboratory and population. Consult laboratory-specific reference values. Typically <1.5 μmol/L in healthy newborns.N/A

Specimen: serum

No special preparation required. This is a newborn screening test typically collected within 24-72 hours of birth.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

The 2-methylcitrate test is primarily used to screen for inherited metabolic disorders, specifically methylmalonic acidemia (MMA) and propionic acidemia (PA). These are rare genetic conditions where the body lacks certain enzymes needed to process proteins and fats properly. Without treatment, these disorders can lead to serious health problems including developmental delays, seizures, organ damage, and life-threatening metabolic crises. Early detection through newborn screening allows for early intervention with special diets, medications, and supplements that can prevent or reduce complications.

Frequently asked questions

Why is this test done on newborns?

This test is part of routine newborn screening because these metabolic disorders can cause serious health problems if not detected and treated early. Newborns with these conditions often appear normal at birth but can develop symptoms within days or weeks. Early detection allows doctors to start treatment before symptoms appear, which greatly improves long-term outcomes.

What happens if the test result is abnormal?

If the 2-methylcitrate level is abnormal, the newborn screening program will contact your healthcare provider. Additional testing will be done to confirm the diagnosis and determine the specific type of metabolic disorder. A genetic counselor or metabolic specialist will discuss treatment options and management strategies with the family.

Can these metabolic disorders be treated?

Yes, these conditions can be managed with proper treatment. Management typically includes a special low-protein diet, formula specifically designed for metabolic disorders, supplements like carnitine and vitamin B12, and close monitoring by a metabolic specialist. With early and ongoing treatment, many children can lead relatively normal lives with fewer complications.

Is the test painful for the baby?

The blood sample is collected from the baby's heel with a small lancet. This may cause brief discomfort or crying, similar to any routine blood draw. The procedure only takes a moment and the small amount of blood needed is collected quickly.

Sources

1
Mayo Clinic Laboratories - Methylmalonic Acidemia PanelSource
2
National Newborn Screening and Global Resource CenterSource
3
MedlinePlus - Newborn Screening TestsSource

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