Maroteaux Lamy syndrome - Enzyme Analysis
|Disease name||Maroteaux Lamy syndrome (MPS VI)|
|Enzyme Name||Arylsulfatase B|
|Clinical info||Maroteaux Lamy syndrome is characterized by short stature, coarse facies, corneal clouding, joint stiffness and contractures and splenomegaly. Other features may include inguinal hernia, obstructive airway disease, skeletal abnormalities and cardiac valve disease. The progression of Maroteaux Lamy syndrome varies among affected individuals, and intelligence is typically not affected.|
|Indications||This test can be used to confirm a suspected Maroteaux Lamy syndrome diagnosis. Prenatal diagnosis and carrier testing via enzyme analysis are not available.|
|Methodology||Quantifies level of arylsulfatase B via the 4-methylumbelliferyl substrate|
|Associated Tests||Urinary excretion of dermatan sulfate is seen which can be assessed via MPS electrophoresis.
Arylsulfatase B enzyme analysis is also part of the MPS Enzyme Panel.
Molecular analysis of ARSB gene is also available for identification of the causative mutation within a family, carrier status and prenatal diagnosis.
Enzyme activity can be measured in leukocytes, cultured fibroblasts, or dried blood spots. For leukocytes, please send 5-10 ml of whole blood in a green top (sodium heparin) tube. For dried blood spot collection, a minimum of three circles needs to be filled in. Each circle should contain one drop of blood (about 100 microliters). See the link below for additional sample collection and handling instructions.
In addition, a dried blood spot or blood drawn in an EDTA tube can be used for Maroteaux-Lamy syndrome molecular analysis and may be sent for DNA banking. Please indicate on the requisition if DNA should be banked for follow-up molecular testing.
Whole blood samples (for leukocyte analysis) should be shipped at ambient temperature and must arrive at the laboratory within 24 hours of specimen collection.
Cultured fibroblasts should be sent overnight at room temperature.
For a dried blood spot: When the sample has dried 3-4 hours, fold cover at score line, over sample, and tuck into flap. Samples should be placed in the mail within 24 hours of collection. Overnight shipping is preferred.
|Turnaround time||14 days
Cell culture can take 1-4 weeks and may lengthen turnaround time.
|Cost||Leukocytes or cultured fibroblasts: $200
Dried Blood Spot Analysis: A 50% discount will be applied for enzyme analysis from a dried blood spot reducing the price to $100.
The Biochemical Lab provides diagnostic and screening tests for a variety of inherited metabolic disorders.