Genetic Testing

In order for us to develop new ways to treat choroideremia, we need to learn more about its symptoms and its genetics. The more we know about this disease, the better equipped we will be in managing and treating it. This is why we are offering research genetic testing at our laboratory for the REP1 gene. Genetic testing allows us to identify the molecular cause of choroideremia. This is separate from our gene therapy clinical trial. In other words, research genetic testing is available to you whether or not you are participating in our clinical trial.

Purpose: To add to our understanding of choroideremia as well as to provide you with more information about your genetic status and what it means to you and your family.

Please click here for the information sheet and consent form.

What is the difference between research and clinical genetic testing?

Research genetic testing

The main purposes of research genetic testing are to understand the disease better and to potentially develop new clinical tests. Research testing is covered by research funding. In Canada, the related doctor or genetic counsellor visits, blood collection and shipping is also usually covered. In the US, these related costs are often the responsibility of the patient. This type of genetic testing is often performed in an academic research laboratory. Research laboratories are not required to meet CLIA standards. They are also not required to provide genetic results to the patient or the provider. The lab may provide results. However, since research genetic testing is not required to meet CLIA testing standards, we recommend that all research results be confirmed by clinical testing.

Clinical genetic testing

The main purpose of clinical genetic testing is to provide the patient with useful medical information for diagnosis, prevention or treatment. Testing costs are the responsibility of the public healthcare system or patient (depending on the situation). Costs can range from $100 to over $2000 depending on the gene(s) tested and the method used. Clinical laboratories are required to meet CLIA standards. A formal report is typically provided in a timely manner to a healthcare provider for the patient. Testing is usually performed in a private or hospital laboratory.

This has been adapted from this US-based Foundation Fighting Blindness document. This document is for general information only. Please speak to your healthcare provider about your specific situation.

I would like genetic testing for the REP1 gene. How do I go about getting this?

It is important that a professional specially trained in genetic counselling is involved to discuss whether genetic testing is right for you.  Approach your doctor for a referral or to find a local genetic counsellor in Canada, use this website. If you are from the US, use this website. Genetic counsellors are also able to coordinate clinical or research genetic testing (through us) and able to help you understand your genetic test result. If this is not possible, we are also available to provide genetic counselling over the phone.

For more details about our research study, review this information sheet and consent form. Please contact our genetic counsellor and study coordinator, Stephanie Chan should you have any questions (info@chmgenetherapy.ca or 780-492-8869).

Can my unaffected daughter have genetic testing to determine her carrier status?

Yes, if she is an adult (18 or older) and a familial mutation has been identified.  It is recommended that you discuss this with a genetic counsellor.

Can my young son who does not have symptoms of choroideremia, have genetic testing to determine his risk of developing choroideremia?

Yes, if a familial mutation has been identified and your son is at risk of inheriting the faulty REP1 gene. It is recommended that you discuss this with a genetic counsellor.