Arylsulfatase A Deficiency, Leukocytes
| Arylsulfatase A Deficiency, Leukocytes | | | |
| Number | | 402396 |
| CPT | | 82657 |
| Synonyms | | ASA Deficiency ; Metachromatic Leukodystrophy (MLD) ; MLD |
| Special Instructions | | Collect specimens Monday through Thursday only. Specimens must arrive in the lab within 48 hours of collection. |
| Specimen | | Whole blood |
| Volume | | 15 mL |
| Minimum Volume | | 10 mL |
| Container | | Yellow-top (ACD) tube |
| Collection | | Refrigerate specimen after collection. Transport to the testing facility using cool pack or LabCorp transport kit. Do not allow the sample to freeze. Specimens must arrive in the testing facility within 48 hours of collection. Collect specimens Monday through Thursday only. |
| Storage Instructions | | Refrigerate |
| Causes for Rejection | | Quantity not sufficient for analysis; specimen frozen; specimen not received within 48 hours of collection; incorrect specimen collection tube |
| Reference Interval | | 25.0-90.0 nmol/hour/mg protein |
| Use | | Diagnose patient with metachromatic leukodystrophy (MLD) |
| Limitations | | This assay does not identify patients with a rare form of MLD due to cerebroside sulfate activator protein deficiency. Unaffected pseudodeficiency homozygotes and compound heterozygotes cannot be distinguished from affected individuals by this assay. ASA activity may not reflect carrier status. |
| Methodology | | Determination of enzymatic activity with p-nitrocatechol sulfate |
| References | | Shapira E, Blitzer MG, Miller JB, et al, Biochemical Genetics: A Laboratory Manual, New York, NY: Oxford University Press, 1989. |
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