Hunter Syndrome – Enzyme Analysis
|Disease name||Hunter syndrome (MPS II)|
|Enzyme Name||Hunter syndrome is caused by a deficiency of iduronate-2-sulfatase|
|Clinical info||Hunter Syndrome is an X-linked condition characterized by coarse facial features, hepatosplenomegaly, dysostosis multiplex, stiff joints, hydrocephalus, and developmental regression.|
|Indications||This test can be used to confirm a suspected Hunter syndrome diagnosis. Prenatal diagnosis and carrier testing via enzyme analysis are not available.|
Urinary excretion of dermatan sulfate and heparin sulfate is seen which can be assessed via MPS electrophoresis.
|Methodology||Quantifies level of Iduronate-2-sulfatase via the 4-methylumbelliferyl substrate|
Enzyme activity can be measured in plasma, cultured fibroblasts, or dried blood spots. For plasma, please send 5-10 ml of whole blood in a green top (sodium heparin) tube OR plasma can removed from spun down sample and sent frozen
For dried blood spot collection, a minimum of three circles need 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 Hunter 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.
|Transport||Whole blood should be sent over overnight at ambient temperature. Plamsa can be removed once the sample has been done and sent frozen on dry ice. Do not freeze whole blood.
Cultured fibroblasts can 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.