Metachromatic Leukodystrophy – Enzyme Analysis
|Disease name||Metachromatic leukodystrophy|
|Enzyme Name||Arylsulfatase A|
|Clinical info||Metachromatic leukodystrophy is an autosomal recessive condition caused by a deficiency of arylsulfatase A, an enzyme crucial to the breakdown of sulfatides in the body. The accumulation of sulfatides causes demyelination of nerves. Progressive signs of leukodystrophy include a decline in intellectual abilities and motor skills to the extent that affected individuals lose the ability to walk, speak, see, and hear. This condition can present as late-infantile, juvenile or adult forms, and it is more common in people of Israeli or Navajo descent.|
|Indications||Patients with a suspected diagnosis of metachromatic leukodystrophy based on clinical symptoms and MRI findings. Prenatal diagnosis and carrier testing via enzyme analysis are not available.|
|Associated Tests||Measurement of arylsulfatase A is included in the Lysosomal Enzyme Panel.
Molecular analysis of the gene for metachromatic leukodystrophy (ARSA) is also available for identification of the causative mutation within a family, carrier status and prenatal diagnosis.
|Methodology||Measurement of enzyme activity via spectrophotomer|
|Specimen Requirements||Enzyme activity can be measured in leukocytes or cultured fibroblasts. For leukocytes, please send 5-10 ml of whole blood in a green top (sodium heparin) tube.|
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.
|Turnaround time||14 days
Cell culture can take 1-4 weeks and may lengthen turnaround time.
The Biochemical Lab provides diagnostic and screening tests for a variety of inherited metabolic disorders.