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Test Code MSUD Maple Syrup Urine Disease

Clinical System Name

Maple Syrup Urine Disease


Amino Acid MSUD monitoring

Branched Chain Amino Acids


Sample Requirements

Specimen:Whole Blood

Container(s):Dark Green/Sodium Heparin, Lt. Green/ Lithium Heparin

Preferred Vol:1 mL

Minimum Vol: 0.5 mL


Note: Serum or EDTA plasma is acceptable but not preferred.


Processing Instructions

Reject due to:

Spin: Y

Aliquot: Y

Temp: -20 C

Storage location: -20 C BCG box


Off-site collection: Spin blood, freeze plasma within 2 hours and ship frozen.


Temperature Time
Room temp ≤2 hr
Refrigerated 24 hrs
Frozen 1 month



STAT Performed TAT
N M-F up to 2 days


Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.


Department: Biochemical Genetics

Phone: 206-987-2216


Reference Range

Age 0 - 1 mo 1 mo - 5 yr 6 yr - adult
Valine (mcmol/L) 70 - 300 75 - 350 120 - 300
Isoleucine (mcmol/L) 20 - 90 27 - 120 30 - 110
Leucine (mcmol/L) 50 - 193 45 - 160 60 - 200
Alloisoleucine (mcmol/L) not present not present not present



Method: Ion exchange chromatography with post column ninhydrin derivatization

Analytical Volume: 0.1 mL plasma



Note: Test includes Valine, Isoleucine, Leucine, and Alloisoleucine

CPT Codes


Special Instructions

Links to:

Consent Forms



Biochemical Genetics Requisition


On the requisition include clinical information needed for appropriate interpretation.  (Age, gender, diet (e.g. TPN therapy), drug therapy and family history)

Clinical Utility

Used for diagnosis and dietary monitoring of patients with maple syrup urine  disease.