Spinocerebellar Ataxia Expansion Panel

Clinical Information

Spinocerebellar ataxia (SCA) refers to a group of neurodegenerative disorders that affect the cerebellum, the region of the brain that controls the coordination of movement. SCA is marked by progressive ataxia or poor coordination of movement. Other features include unsteady gait, poor hand coordination, involuntary eye movements, and slurred speech. Cognitive decline can be seen in certain types of SCA. The age of onset of SCA is extremely variable and ranges from childhood to late adulthood.

Trinucleotide repeat expansions are one genetic cause for SCA with SCA 1, 2, 3, 6, and 7 accounting for ~60% of dominant ataxias in North America. These ataxias result from trinucleotide repeat expansion, and the size of the repeat expansion is typically correlated with age on onset and rate of progression.

Specimen Requirements

• The preferred sample type is 3-4 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA and saliva are also accepted for this test. Blood and saliva kits are available by request.
• Send approximately 5µg of extracted DNA at a requested concentration of 90-130 ng/µl.
• Saliva samples must be submitted in an approved saliva kit, and sample kits are available upon provider request.

Transport Instructions

• The blood specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.
• Extracted DNA should be sent at room temperature via overnight delivery.
• Saliva is stable at room temperature and can be delivered via overnight or ground shipping.