Beta-Galactocerebrosidase, Dried Blood Spot (Referred Out) - Saskatoon
Discipline
Biochemistry
Overview
Description
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
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Krabbe’s disease
- Globoid cell leukodystrophy
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Galactocerebrosidase deficiency
Specimen Information
Specimen types accepted
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Whole blood
Specimen collection container
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Preferred collection container: Dark Green (Lithium Heparin) 4.0 mL
- Alternate collection container: Lavender (EDTA) 4.0 mL
- Alternate collection container: Dark Green (Sodium Heparin) 4.0 mL
Required volume
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Optimal volume: 4.0 mL whole blood
- Minimum/pediatric volume: 1.0 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 and shipped to referral laboratory at ambient temperature.
Rejection criteria
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Specimens received where the proper collection protocols were not followed
- Pathology and Laboratory Medicine Acceptance and Rejection Criteria
Testing Information
Relevant clinical history
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Family history
- Must include diagnosis and/or patient symptoms on the requisition
Clinical interpretation
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Results should be interpreted in the context of patient history, clinical findings and other laboratory data
Performance
Methodology
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Quantifies level of beta-galactocerebrosidase via the 4-Methylumbelliferyl substrate
Days/times performed
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| Testing Site |
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Maximum laboratory time
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2 week turnaround time by referral laboratory
Other information
Additional comments
- Beta-Galactocerebrosidase enzyme activity is useful for the diagnosis of Krabbe disease.
- Krabbe disease is an autosomal-recessive genetic condition caused by defects in the GALC gene (chromosome 14q31), which encodes the enzyme galactocerebrosidase (GALC). GALC deficiency leads to accumulation of galactolipids within the lysosome, subsequently resulting in defective myelin production and affecting the CNS white matter and myelination of peripheral nerves. Krabbe disease is classified as infantile- onset or later-onset "classic" disease. The more common infantile form (80-90% of diagnosed patients) presents with irritability, spasticity, and hypertonia in the first months of life with rapid neurologic regression. Death usually occurs before age 2. Approximately 10-15% of patients present between the first year of life and the fifth decade of life with a variable onset of vision disturbance/loss, weakness and cognitive decline. (Reference: laboratory diagnosis of inherited metabolic diseases, Edited by Uttam Garg, Laurie D. Smith, Bryce A Heese)
Last Updated: October 3, 2024