Genetic testing services for HSP
Genetic testing services offer valuable data to neurologists, clinical geneticists and family doctors in the provision of good healthcare information, advice and recommendations by:
- Providing positive confirmation of clinical diagnoses – doctors rely mostly on physical symptoms in diagnosing HSP in clinical examinations and the condition is not uncommonly mis-diagnosed. Similarly, other diseases are not uncommonly mis-diagnosed as HSP.
- Screening services for family members where there is a known HSP mutation in a blood relative.
- Helping with family planning choices for HSPers in the quest to have children free of their HSP mutation. Read about the benefits and considerations in genetic testing for family planning.
Four HSP genetic testing services are available in Australia
As at May 2016 there are 4 genetic testing laboratories for HSP in Australia that are available to all Australians at risk of HSP through your local genetics testing service. Two are located in NSW, one in Victoria and the other in WA. Neurologists and geneticists no matter where they are located can use the service of choice for their HSP patients, including the choice to use overseas services for various reasons and purposes. They, along with genetic counsellors, will talk with you about their preferred service and what that means for you in terms of the tests that will be conducted and costs, if any, associated with that.
1. Molecular Medicine Laboratory, Concord, Sydney
The MolMed lab at Concord Hospital in Sydney was the first in Australia to offer genetic testing for HSP. The current service offered includes 51 HSP genes MolMedHSPgenelist (.pdf file). Here is the process:
- Patients can visit their neurologist to discuss and request genetic testing, or the neurologist might suggest it. A lot of information is required for the Request Form MolMed EXOME FORMS (.pdf file) to guide and assist testing. A neurologist or clinical geneticist is ideal for requesting genetic testing.
- The genetic testing process in the lab starts with the Request Form that has been completed by a combination of the patient’s medical professionals and the patient or guardian themselves.
- The initial testing task is to screen the 51 HSP genes using next-generation exome sequencing.
- If no mutation is found, there is a search for mutations in a wider range of selected genes.
- All the patient data can be stored and as new HSP genes are identified, there is the capability to come back and check the new genes for the patient. Newly discovered genes are added to the gene panel systematically.
- There are plans to start using whole genome next generation sequencing technology in future. This will be where no mutation is identified in the initial exome screen, then searching the whole genome for potential candidate genes will be carried out.
- This is a diagnostic service where a mutation, if identified, will be confirmed. Results are provided to the referring medical professional.
- Traditional Sanger sequencing/copy number variation testing for the three major HSP genes, that is Spastin, Atlastin and REEP1, is still available*.
- Screening for known genes e.g. for other family members when one member has a known mutation, is another service that is offered.
The cost for the testing is currently $1,800 for the 51 gene panel and $2,400 for the ‘whole exome plus’ panel.
The timeline for testing and providing results is around 6 months.
Some public hospitals will pay for the service. Patients need to find out options and requirements with their hospital to determine the situation regarding costs.
2. HSP clinic, Royal North Shore Hospital, Sydney
The HSP clinic at Royal North Shore hospital in Sydney, headed up by Dr Carolyn Sue, diagnoses and reviews the status of people with suspected or confirmed HSP. Genetic testing is then decided on a case-by-case basis and individually tailored to the clinical scenario and clinical features observed. The genetic testing service offered currently is being further developed and includes the latest next generation technologies and methodologies.
3. Victorian Clinical Genetics Services Neurogenetics Laboratory, Melbourne
Victorian Clinical Genetics Services (VCGS) http://www.vcgs.org.au/ delivers expert genetic testing and genetic support services to thousands of families in Victoria, throughout Australia, and around the world. For HSP, they provide an exome test where the referring doctor can specify a list of HSP genes for analysis.
4. PathWest Neurogenetics Laboratory, QEII Medical Centre, Nedlands, Perth
The PathWest neurogenetics lab in WA has both next-generation and traditional sequencing technologies to test 70 HSP genes PathWestHSPgenelist (Excel spreadsheet). They have testing panels for more than 10 categories of neuromuscular/neurodegenerative conditions including Charcot-Marie-Tooth disease, motor neurone disease, mitochondrial disorders, ataxias, dystrophies and dystonia.
* MolMed traditional testing service for the 3 major HSP genes is still available.
This is for the detection of mutations in:
- SPG4 (spastin)
- SPG3A (atlastin)
- SPG31 (REEP1) and also
- Screening of these for known family mutations.
|SPG4 or 3A only
|All 3 genes
The process is that the Doctor requesting the test completes and signs the request form with the patient and sends it to the laboratory. Administrative issues such as specifying the type and scope of the particular test requested, costs involved and an agreement concerning consent and costs are then dealt with between the laboratory, the requesting doctor and the patient. The signed agreement is then returned to the laboratory, often accompanying the blood sample.
Where the patient goes through the public hospital system, there is often an existing arrangement that covers the costs involved in testing. These arrangements vary from State to State, and may also vary between regions or health service areas within a particular State or Territory, or even from hospital to hospital. Check with your doctor or genetic counsellor about these arrangements and relevant procedural details when first considering genetic testing.
To be a candidate for testing, a neurologist must first conclude that an individual may have, or be at risk of having HSP. From there, it is on to a clinical genetics service. Genetic counselling services for all States and Territories of Australia and for New Zealand are listed.
If you can’t access the web, phone your local public hospital and, if they do not have a genetics service or genetics counselling service they will tell you the closest hospital that does. Clinical Geneticists are doctors and a referral is not required. If you prefer, ask your neurologist for a contact.
A well-established protocol is followed. This includes the important role of genetic counselling which involves a genetic counsellor gathering and recording genetic information and family relationships on your family tree, helping you understand options and implications, offering guidance and support to help you make informed choices, and to help you understand and deal with test results when they become available. All information gathered is maintained by the genetic counsellor and privacy is strictly observed even within the family. The Clinical Genetics service, apart from the cost of the genetic test, is a service provided free by the State in most cases where people come through the public hospital system.
HSPers should seek genetic counselling to help understand the ramifications of knowing the family mutation and the benefits for current and future generations. Individual family members can consider the simple screening test and discuss it with the same counsellor once the family mutation has been positively identified by genetic testing in one blood relative.
An individual family member who learns from screening that they carry an HSP mutation will benefit from discussion of life choices ahead of possible onset, including things such as early intervention physical therapy to maintain mobility and quality of life to the greatest extent possible. Even if someone who tests positive never develops HSP symptoms, understanding parenting issues and reproductive choices is highly recommended.
Learn more about Genetic Counselling.
Genetic Testing Technology
Technology used for next-generation sequencing (NGS) of DNA has rapidly developed since 2010, with the result that the availability of testing, the cost and the time that it takes to read an individual’s DNA is getting better and better. Consequently, new genome technologies like NGS are steadily being adopted worldwide for use in the diagnosis of genetic disorders such as HSP.
Complex questions on issues such as data sharing and informed consent are constantly being addressed due to the confidential nature of personal data produced by such technologies and the demands for using such data for research and related purposes. The challenge is how to harness the potential of these technologies for health care while respecting fundamental ethical and regulatory frameworks.
To ensure that the expectations and needs of society, and in particular those with genetic conditions, are met in the broad implementation of these technologies, relevant stakeholders (patient representatives, genomics researchers, clinical geneticist, bioinformaticians, policy makers, ethics experts etc.) need to be engaged in this dialogue and subsequently produce recommendations that achieve widespread acceptance.