Test Code LALBS Lysosomal Acid Lipase, Blood Spot
Useful For
Evaluation of patients with a clinical presentation suggestive of lysosomal acid lipase deficiency using blood spot specimens
This test is not useful to determine carrier status for cholesteryl ester storage disease or Wolman disease.
Reporting Name
Lysosomal Acid Lipase, BSSpecimen Type
Whole bloodNecessary Information
Provide a reason for testing with each specimen.
Specimen Required
Supplies: Card-Blood Spot Collection (Filter Paper) (T493)
Collection Container/Tube:
Preferred: Blood spot collection card
Acceptable: PerkinElmer 226 filter paper, Munktell TFN, and Whatman Protein Saver 903 Paper
Specimen Volume: 2 Blood spots
Collection Instructions:
1. Completely fill at least 2 circles on the filter paper card (approximately 100 microliters blood per circle).
2. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.
3. Let blood dry on the filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.
4. Do not expose specimen to heat or direct sunlight.
5. Do not stack wet specimens.
6. Keep specimen dry.
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions.
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777).
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800).
Specimen Minimum Volume
1 Blood spot
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Refrigerated (preferred) | 28 days | FILTER PAPER |
Frozen | 90 days | FILTER PAPER | |
Ambient | 7 days | FILTER PAPER |
Reject Due To
Shows serum rings Multiple layers |
Reject |
Clinical Information
Deficiency of lysosomal acid lipase (LAL) results in 2 clinically distinct phenotypes, Wolman disease (WD) and cholesteryl ester storage disease (CESD). Both phenotypes follow an autosomal recessive inheritance pattern and are caused by variant in the LIPA gene.
WD, the early-onset phenotype of LAL deficiency, is a lipid storage disorder characterized by vomiting, diarrhea, failure to thrive, abdominal distension, hepatosplenomegaly, and liver failure. Enlarged adrenal glands with calcification, a classic finding in WD, can lead to adrenal cortical insufficiency. Unless successfully treated, survival is rare beyond infancy.
CESD, the late-onset phenotype of LAL deficiency, is clinically variable with patients presenting at any age with progressive hepatomegaly and often splenomegaly, serum lipid abnormalities, and elevated liver enzymes. In childhood, patients can also present with failure to thrive and delayed milestones. Common features include premature atherosclerosis leading to coronary artery disease and strokes, liver disease of varying severity, and organomegaly. Lipid deposition in the intestinal tract can lead to diarrhea and weight loss.
CESD is likely underdiagnosed and frequently diagnosed incidentally after liver pathology reveals findings similar to nonalcoholic fatty liver disease or nonalcoholic steatohepatitis. Birefringent cholesteryl ester crystals in hepatocytes or Kupffer cells in fresh-frozen tissues are visualized under polarized light and pathognomonic.
Enzyme replacement therapy (sebelipase alfa) was recently approved for both WD and CESD and is now clinically available.
Reference Values
≥21.0 nmol/h/mL
Interpretation
Enzyme activity below 1.5 nmol/h/mL in properly submitted samples is consistent with lysosomal acid lipase deficiency: Wolman disease or cholesteryl ester storage disease.
Normal results (≥21.0 nmol/h/mL) are not consistent with lysosomal acid lipase deficiency.
Day(s) Performed
Friday
Report Available
8 to 15 daysSpecimen Retention Time
1 yearPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82657
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LALBS | Lysosomal Acid Lipase, BS | 73958-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
62955 | Lysosomal Acid Lipase, BS | 73958-1 |
36341 | Reviewed By | 18771-6 |
36340 | Interpretation (LALBS) | 59462-2 |
Method Name
Fluorometric Enzyme Assay
Special Instructions
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Biochemical Genetics Patient Information (T602)
3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
Genetics Test Information
This test provides diagnostic testing for patients with clinical signs and symptoms suspicious for lysosomal acid lipase deficiency (LALD).
LALD is expressed phenotypically as infantile-onset Wolman disease or later-onset cholesterol ester storage disease.