Mucolipidosis II, III Screen Dried Blood Spot, Blood (Referred Out) - Saskatoon
Discipline
Biochemistry
Overview
Description
- This test measures the activities of four lysosomal hydrolases from a dried blood spot, including acid sphingomyelinase, alpha-iduronidase, beta-glucosidase, and alpha-mannosidase.
Test ordering requirements
Forms required
- Requisitions must have specific test indicated
- Miscellaneous Specimen Requisition Form #101878 or SHR Laboratory Medicine Community Laboratory Requisition Form #101064 or Acute Care Phlebotomy Requisition Form #101062
Alias
- I – Cell (ML II)
- Pseudo – Hurler (ML-III)
Specimen Information
Specimen types accepted
- Whole blood
Specimen collection container
- Preferred collection container: Dark Green (Lithium Heparin) 4.0mL
- Alternate collection container: Dark Green (Sodium Heparin) 4.0mL
- Alternative collection container: Lavender (EDTA) 4.0mL
Required volume
- Optimal volume: 4 mL whole blood
- Minimum/Pediatric Volume: 1 mL whole blood
Transport and stability
- Whole blood must be received within 24 hours of collection
- Store whole blood at room temperature
- Neonatal Screen Card should be spotted with whole blood within 24 hours of collection.
- Once spotted, the Neonatal Screen Card should be allowed to dry for 3-4 hours & shipped to referral laboratory at ambient temperature.
Rejection criteria
- Specimens received where the proper collection protocols were not followed
- Pathology and Laboratory Medicine Acceptance and Rejection Criteria
Testing Information
Relevant clinical history
- Family history
- Must include diagnosis and/or patient symptoms on the requisition.
Clinical interpretation
- The results should be interpreted in the context of clinical findings and other laboratory data.
Performance
Methodology
- Spectrophotometric/ Fluorometric Enzyme Assay
Days/times performed
Availability |
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Testing site |
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Maximum laboratory time
- 2 week turnaround time by referral laboratory
Other information
Additional comments
- The Neonatal Screen card will be spotted when whole blood received in the lab.
- Mucolipidosis type II (known as I-cell disease) and mucolipidosis IIIA (also known as pseudo-Hurler polydystrophy) are cause by mutations in the enzyme N-acetylglucosamine-1-phosphotransferase. This enzyme is required for the synthesis of mannose-6-phosphate recognition markers for enzymes transport to the lysosome. Without this marker, hydrolytic enzymes cannot be properly transported to the lysosomes. In turn, the hydrolases are secreted into the extracellular medium. Increased lysosomal hydrolase activities in the plasma is consistent with a diagnosis of Mucolipidosis II/III
Last Updated: October 3, 2024