Prion proteingene (PRNP) Test Protocol
What is the PRNP test?
The PRNP test is a genetic test, where DNA from an individual is analysed for the presence of mutations associated with genetic prion diseases. DNA can be extracted from blood or brain tissue samples for the purpose of testing.
Genetic or familial prion disease comprises approximately 10 -15% of all cases of prion disease.
The prion protein gene (PRNP) is located on chromosome 20. Polymorphisms coded on the prion protein gene are also identified and routinely reported, including the polymorphic risk factor found at Codon 129. Polymorphisms do not cause CJD, but they may influence the illness.
When are samples collected?
Blood samples can be collected from patients suspected or diagnosed with clinical CJD and stored long term at the ANCJDR. Samples from autopsy tissues may also be used for PRNP testing.
PRNP testing is not undertaken on available samples unless documented consent has been provided to the ANCJDR, organised by the requesting Doctor or Genetic Counselling service.
Testing for genetic CJD often raises significant medical, ethical, psychological, and legal issues for all living blood relatives. Consultation with a specialist clinician or a clinical genetics service is necessary to ensure that the requesting individual/family fully understand/s the test procedure, benefits, limitations and the possible consequence of the test result.
Symptomatic or deceased patients
PRNP testing will only proceed when the ANCJDR has received a copy of a consent form from the requesting doctor. Documented consent records that the consenting individual is giving ‘informed consent’ for this specific test. In the majority of instances, consent for testing will need to be given by a lawful next of kin (NOK) due to cognitive impairment accompanying prion diseases during an illness or the patients deceased status.
Please use the local health service genetic testing consent form, and if one is not available, please contact the ANCJDR.
Testing will proceed once documented consent has been provided to the ANCJDR, organised by the requesting Doctor, as per the ANCJDR test schedule (see below).
The ANCJDR does not provide testing for individuals who are not experiencing symptoms of CJD, but who are concerned about their own risk for genetic CJD. In these situations, all individuals are able to access testing through the local genetic counselling services as per HGSA guidelines for Pre-symptomatic and Predictive Testing for Genetic Disorders http://www.hgsa.org.au/documents/item/1574
- 4 mls in EDTA tube
- Stored at 4oC
- DO NOT FREEZE
- PLEASE NOTIFY REGISTRY STAFF THE SAMPLE IS BEING SENT.
Please note samples can only be delivered between 9 - 4PM weekdays, addressed to:
The Australian National CJD RegistryPhone: (03) 8344 1949
Dept. of Pathology, Faculty of Medicine
The University of Melbourne
Melbourne Brain Centre (Kenneth Myer Building)
Cnr Genetics Lane and Royal Parade
Gate 11, Rear Loading dock
Parkville, Victoria 3052
Fax: (03) 9349 5105
Diagnostic Testing Fees
Refer to Diagnostic pricing schedule
2014 testing Schedule
The ANCJDR offers PRNP testing three times per year. A two month window is allocated to allow flexibility with planning and consent processes.
Please be aware results will ONLY be issued directly to the requesting clinician. The referring clinician will be responsible for disseminating results to the family.