Leucine

ChemistryAlso known as: 2-amino-4-methylpentanoic acidAlso known as: L-leucinemg/(24.h)

Measures leucine, an essential amino acid, in serum or plasma collection.

Normal Range

15 – 80 mg/(24.h)

mg/(24.h)

Abnormal Levels

Consult your provider

Specimen Type

Blood

Why This Biomarker Matters

Abnormal leucine levels may indicate serious inherited metabolic disorders like maple syrup urine disease. Early detection through this test prevents severe neurological complications.

Understanding Your Results

Normal Range

15 – 80 mg/(24.h)

Overview

Leucine is an essential branched-chain amino acid crucial for muscle protein synthesis and energy metabolism. A 24-hour urine leucine test measures how much of this amino acid your body is excreting over a full day. Abnormal urinary leucine levels may indicate inherited metabolic disorders like maple syrup urine disease (MSUD), kidney dysfunction, or severe nutritional deficiencies. This test is particularly important in newborn screening and evaluation of patients with neurological symptoms or developmental delays.

Technical Information (LOINC Codes)

Standardized laboratory codes for this biomarker

20649-0Primary

Leucine [Moles/volume] in Serum or Plasma

umol/L

2562-7

Leucine [Mass/time] in 24 hour Urine

mg/(24.h)

2561-9

Leucine [Mass/volume] in Urine

mg/dL

47679-6

Leucine [Moles/volume] in DBS

umol/L

2559-3

Leucine [Presence] in Serum or Plasma

2560-1

Leucine [Mass/volume] in Serum or Plasma

mg/dL

25460-7

Leucine [Moles/time] in 24 hour Urine

umol/(24.h)

22719-9

Leucine [Moles/volume] in Specimen

umol/L

9412-8

Leucine [Moles/volume] in Cerebral spinal fluid

umol/L

55933-6

Leucine [Moles/mass] in Hair

umol/g

26710-4

Leucine [Moles/volume] in Amniotic fluid

umol/dL

25941-6

Leucine [Moles/volume] in 24 hour Urine

umol/L

13403-1

Leucine [Mass/volume] in Amniotic fluid

mg/dL

27323-5

Leucine [Moles/volume] in Urine

nmol/mL

29284-7

Leucine [Presence] in Blood

29293-8

Leucine [Mass/volume] in Blood

mg/dL

32253-7

Leucine [Moles/volume] in Vitreous fluid

umol/L

32254-5

Leucine [Moles/volume] in Body fluid

umol/L

49834-5

Leucine [Presence] in Urine

Available Lab Tests

Order tests that measure this biomarker

Amino Acids (Plasma)

$193.00

Results in 3-7 business days