Lysosomal Acid Lipase Enzyme Analysis
Related Gene(s): LIPA
Lysosomal acid lipase (LAL) activity assay is indicated in patients with clinical signs and symptoms suggestive of Wolman disease (WD) or cholesteryl ester storage disease (CESD). Human LAL hydrolyses cholesteryl esters and triglycerides in lysosomes. Deficiency of LAL results in WD or CESD, which are autosomal recessive disorders with an estimated incidence of 1 in 500,000 (WD) and 1 in 40,000 (CESD).
Wolman disease is an early-onset fulminant disorder of infancy with massive infiltration of the liver, spleen, and other organs by cholesteryl esters and triglycerides. Death occurs early in life. CESD is commonly identified in childhood or adolescence with primary hepatic involvement of cholesteryl ester storage. CESD has a variable clinical spectrum ranging from early onset with severe cirrhosis to later onset with more slowly progressive hepatic disease and survival into adulthood.
Significantly decreased LAL activity (less than 5-10% of normal) is indicative of WD or CESD, which is then confirmed with LIPA sequencing analysis for identification of the disease causing mutations. LAL activity is measured in leukocytes using flurogenic 4-MU oleate substrate and LAL inhibitor lalistat 2 for subtracting the non-LAL lipases.
- Anticoagulated blood: 5-10 mL in ACD tube (yellow top) is preferred. Sodium (or lithium) heparin tubes (green top) or EDTA tubes (lavender top) are also accepted
For newborns or children
- Blood: 3 mL in pediatric EDTA tube (lavender top) or 2 mL in pediatric ACD tube (yellow top) from the patient
- Ship at room temperature; sample must be received within 72 hours of collection
- If the sample cannot be sent within 72 hours, centrifuge immediately and freeze plasma and leukocyte pellets. Then, ship frozen on dry ice
- 7 days