Spinobulbar Muscular Atrophy Repeat Expansion Testing



The AR CAG repeat expansion has been shown to be the cause of X-linked spinobulbar muscular atrophy (SBMA) / Kennedy disease; a very rare disease clinically characterised by slowly progressive muscle weakness and atrophy with onset in adult males (usually in the fourth or fifth decade). Muscle cramps may precede the onset of weakness by several years. Symptoms are related to both spinal and bulbar motor neuron degeneration, including facial weakness, muscle weakness and atrophy, speech difficulty and coarse fasciculation. Affected individuals often show gynaecomastia, testicular atrophy and reduced fertility, as a result of mild androgen insensitivity.

Testing at WRGL

Fluorescent PCR is used to perform this testing. The results of the assay can be visualised using GeneMarker software following fragment analysis on a genetic analyser. Positive and negative controls are included in each assay.

Cost, Sample Requirements & Turnaround Times

Test Cost NZD Sample requirements Turnaround time
AR CAG repeat expansion test $158 4ml of whole blood in EDTA (lavender top) 2 - 4 weeks
For urgent cases please contact the laboratory

*No direct charge for the central region DHBs covered by the Crown Funding Agreement

Spinobulbar muscular atrophy (SBMA) / Kennedy disease testing


Wellington Regional Genetics Laboratory (WRGL) provides a comprehensive, integrated diagnostic cytogenetic and molecular genetic testing service

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(04) 918-5352

Please note that genetic test results are only released directly to the referring clinician and not to patients