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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Amino Acid Analysis for MSUD, Plasma
Test Code19779
CPT Codes
82136
Includes
Valine
Isoleucine
Leucine
Alloisoleucine
Isoleucine
Leucine
Alloisoleucine
Preferred Specimen
2 mL plasma collected in an EDTA (lavender-top) tube, or a sodium or lithium heparin (green-top) tube
Patient Preparation
Collect plasma specimens after an overnight fast (or at least 4 hours after a meal). Include date of collection and age of patient. (Age must be provided for the interpretation and age related reference ranges to print on the report.
Minimum Volume
0.25 mL
Other Acceptable Specimens
Instructions
Separate plasma from cells as soon as possible and freeze below -20°C.
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 30 days
Refrigerated: 7 days
Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Samples received Room Temperature
Methodology
Chromatography/Mass Spectrometry
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Set up: Mon-Fri; Report available: 5-8 days
Reference Range
| Valine | |
| ≤30 days | 57-250 umol/L |
| 31 days-23 months | 84-354 umol/L |
| 2 years-17 years | 130-307 umol/L |
| ≥18 years | 132-313 umol/L |
| Isoleucine | |
| ≤30 days | 12-92 umol/L |
| 31 days-23 months | 10-109 umol/L |
| 2 years-17 years | 33-97 umol/L |
| ≥18 years | 34-98 umol/L |
| Leucine | |
| ≤30 days | 23-172 umol/L |
| 31 days-23 months | 43-181 umol/L |
| 2 years-17 years | 65-179 umol/L |
| ≥18 years | 73-182 umol/L |
| Alloisoleucine | <1 umol/L |
Clinical Significance
Amino acid analysis is necessary for the diagnosis of a variety of inborn errors of metabolism. These include, but are not limited to, phenylketonuria, tyrosimemia, citrullinemia, non-ketotic hyperglycinemia, maple syrup urine disease, and homocystinuria. The assay is also key for the continued monitoring of treatment plans for these disorders and useful for assessing nutritional status of patients. Our methodology is highly accurate at very low levels as well as at elevated levels.
Performing Laboratory
| Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
| 33608 Ortega Highway |
| San Juan Capistrano, CA 92675-2042 |
