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Lab Dept:
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Urine/Stool
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Test Name:
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HEX4 (GLUCOSE TETRASACCHARIDE, URINE FOR POMPE DISEASE)
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General Information
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Lab Order Codes:
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HEX4
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Synonyms:
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Urine Glucose Tetrasaccharide (Hex4) for Pompe Disease; Pompe Disease; HEX4, Urine; Acid Maltase Deficiency; GSD Type II
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CPT Codes:
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82570 – Creatinine; other source
83789 – Mass spectrometry and tandem mass spectrometry, analyte not elsewhere specified; quantitative, each specimen
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Test Includes:
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Hex4 concentrations are measured relative to creatinine and reported as a normalized Hex4 in mmol/mol creatinine.
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Logistics
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Test Indications:
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Useful for the diagnosis of Pompe disease and to monitor patients on enzyme replacement therapy.
As a monitoring tool, urine Hex4 can be used as an indirect measure of the degree of skeletal muscle glycogen clearance in patients with Pompe disease receiving enzyme replacement therapy.
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Lab Testing Sections:
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Urine/Stool - Sendouts
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Referred to:
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Duke University School of Medicine
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Monday - Thursday
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Turnaround Time:
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10 – 14 days
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Special Instructions:
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Provide the time of last meal for the patient.
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Specimen
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Specimen Type:
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Urine
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Container:
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Plastic leakproof container (No preservative)
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Draw Volume:
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1 mL (Absolute Minimum: 0.25 mL)
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Processed Volume:
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Same as Draw Volume
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Collection:
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Random urine collection, void or catheterized
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Special Processing:
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Lab Staff: A well-mixed aliquot should be placed into a screw-capped round bottom plastic vial. Freeze and ship on dry ice. Specimens can only be shipped Monday – Thursday overnight. There are no Saturday deliveries. Include the Duke Biochemical Genetics Request Form with the specimen.
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Patient Preparation:
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None
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Sample Rejection:
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Mislabeled or unlabeled specimens
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Interpretive
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Reference Range:
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Age Specific Hex4 Normalized Control Ranges
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Age
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Result (mmol/mol creatinine)
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<6 months:
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<19
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6 months – 1 year:
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<14
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>1 year:
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<4
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Critical Values:
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N/A
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Limitations:
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Biochemical test results depend in part on the clinical and dietary status at the time of specimen collection. A normal or non-diagnostic test result does not rule out the possibility of an underlying metabolic disorder, including that for which the test was requested.
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Methodology:
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Mass Spectrometry
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References:
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Duke University Medical Center Biochemical Genetics Laboratory (April 2011)
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