Comprehensive Spinocerebellar Ataxia Repeat Expansion Panel

Casandra

Casandra Test Code LC09247Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 620167CPT Codes 81177, 81178, 81179, 81180, 81181, 81182, 81183, 81184, 81343, 81344, 81479

Comprehensive Spinocerebellar Ataxia Repeat Expansion Panel

Clinical Use

Order Test

Use

The Comprehensive Spinocerebellar Ataxia Repeat Expansion Panel is used for diagnostic testing of spinocerebellar ataxias. This genetic analysis is crucial for identifying pathogenic nucleotide repeat expansions in genes associated with spinocerebellar ataxias. It helps in diagnosing patients presenting with progressive incoordination of gait and is often accompanied by poor coordination of hands, speech, and eye movements due to the degeneration of the cerebellum or its connections, without significant cognitive decline.

Special Instructions

Follow proper phlebotomy techniques for whole blood collection. For oral swabs, ensure instructions provided with the kit are followed carefully. Contact MNG Genetic Services for guidance when submitting extracted DNA specimens.

Limitations

False positives or negatives may occur due to insufficient information about rare variants, allele dropout, blood transfusions, bone marrow transplantations, somatic or tissue-specific mosaicism, or sample labeling errors. The test has a maximum reportable range for repeat expansions: ATN1 up to 110 repeats; ATXN1, ATXN2, ATXN3, ATXN7, and ATXN8/ATXN8OS up to 150 repeats; ATXN10 up to 70 repeats; CACNA1A up to 145 repeats; CNBP approximately 75 repeats; DMPK up to 150 repeats; FXN up to 1300 repeats; HTT and JPH3 up to 100 repeats; NOP56 and PPP2R2B up to 65 repeats; and TBP up to 120 repeats. Repeat sizes larger than the stated ranges will be reported as above the maximum reportable repeat size.

Test Details