Genetic counselling and genetic testing
What is Genetic Counselling?
The purpose of genetic counselling is to provide the support and information that a patient in a genetic clinic needs, and to promote informed and autonomous decision-making. It is the process of helping people to understand and adapt to the medical, psychosocial and familial implications of a genetic result.
What does the genetic counselling session involve?
Following the clinical determination by an ophthalmologist that a genetic eye disease may be present, a genetic counselling session will begin with taking a family and medical history (pedigree).
It may then proceed with a discussion regarding the nature of genetic inheritance and different inheritance patterns, as well as current research and helpful resources for the patient.
It may involve genetic testing which will include:
- A consenting process, followed by
- Taking a blood sample or sometimes a saliva sample from a patient and sometimes other family members
- The samples will then be sent for genetic analysis
- This involves interpreting the genetic or molecular data in the context of the clinical findings and assessing the risk of the condition recurring in other family members
Once the results are available they will be explained and discussed (by letter, over the phone or at the next clinic visit), highlighting the individual and familial implications. The patient will be counselled about the interpreted findings and their implications.
Benefits of genetic testing
With the advancement of technology and our increasing understanding of the human genome, genetic testing is now more widely available and accurate, benefiting patients in multiple ways. These include:
- Confirm or rule out a specific inherited condition
- Provide a more accurate risk of developing or passing on a specific condition
- Increase the accuracy of diagnosis, giving some peace of mind
- Assist in family planning
- Pave the way for participation in clinical trials of new treatments
- Contribute to research where the discovery of new genes or specific genetic mutations will be informative for future trials
Limitations of genetic testing
Although there are many benefits to genetic testing, there are still limitations that patients should be aware of before proceeding with testing. These include:
- Limited information about an inherited condition. Sometimes the test cannot predict:
- If a person will show symptoms OR
- How severe the symptoms will be OR
- Whether the disorder will progress over time
- Emotional implications associated with a genetic result including feelings of stress, sadness, anxiety and guilt
- Creating tension within a family because results can reveal information about other family members in addition to the person who is tested
- A result might occasionally affect a patient’s plans regarding having children. Patients can be referred to a Clinical Genetics Service to discuss their reproductive options.
- Concerns about the possibility of genetic discrimination in employment or insurance
- The result, while providing a molecular diagnosis, does not usually change the management of a condition as there are not necessarily any treatment strategies available
Interested to be genetically tested?
There are a number of patients who have been diagnosed with an inherited eye disorder but did not undergo any genetic testing. If you are in a similar situation and would like to undergo genetic testing, you can ask your GP or ophthalmologist to refer you to the Moorfields Genetic Eye Disease service.