Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder located on chromosome 12 that is characterized by progressive myoclonus, epilepsy, ataxia choreoathetosis and dementia.  DRPLA is of special interest because it can closely resemble the symptoms of Huntington disease and the SCAs.  DRPLA has an onset between 20 and 70 years of age and also displays genetic anticipation.  The disease is most commonly found in Japan, but it has also been identified in other regions including the United States. DRPLA is in the class of trinucleotide repeat conditions in which there is an inappropriate expansion of a CAG repeat in the gene.  The unaffected population has between 5 and 25 CAG repeats.  Affected patients have more than 50 repeats.

• Individuals with symptoms similar to Huntington disease, shown to be HD negative by DNA analysis. 
• Individuals at risk of inheriting DRPLA who want to have a better knowledge of their risk.
• Individuals at risk who wish prenatal diagnosis.

• For ambiguous patients, this test may be ordered as part of the Neurological Panel.

• Fluorescent PCR sizing of the CAG region of the gene.

• Blood EDTA (purple top) tubes:  

            Newborn: minimum 1-2 mL          

            Child/Adult: prefer 2 tubes of 3-5 mL

• Prenatal testing: Please contact the laboratory for instructions.

TURNAROUND TIME:     10 working days

CPT CODES: