Genetic Counselling
This page is intended to give you an overview of the genetic counselling process. There may be variations between centres, so if you have any questions, it may be best to contact your local Clinical Genetics service directly. You can be referred through your GP.
What is genetic counselling?
Genetic counselling appointments are opportunities for you and your partner to discuss your child’s genetic diagnosis with a trained healthcare professional. Your genetic counsellor will be able to explain more about chromosomes and trisomy 13 or 18, and will answer any questions you have about the results of your child’s genetic testing. They will also discuss whether you would like genetic testing yourselves.
What to expect in your appointment
Your appointment may be in person, over the telephone or through a video call. You will be encouraged to attend with your partner. If you would like, you can bring a support person with you, such as a friend or relative. The appointment will last for around 45 minutes (depending on the centre). During the appointment, your genetic counsellor will ask you questions about your family history and may ask you about whether you are planning to have any other children in future. They do this because, in a small number of cases, a parent might have a typical number of chromosomes (i.e., 46), but these chromosomes are arranged in such a way that it makes it more likely for their children to inherit an additional copy of a particular chromosome. Genetic counsellors will talk to you about whether you would like to have genetic testing to find out whether your chromosomes are arranged in this way (this is called having a ‘balanced translocation’) or not. If you decide to have a genetic test, you may be asked to sign a consent form (if your appointment is in person). Your genetic counsellor will also discuss how you would like to receive your genetic test results (i.e., phone call, in person appointment, video call or letter) and they should give you an indication of how long you will have to wait to receive the test results.
During the appointment, you should have the opportunity to ask any questions you have.
What does genetic testing involve?
If you decide to have a genetic test, you may be given a form to take to a phlebotomist to have a blood sample taken. This sample will be sent to a laboratory for testing. Once the results are ready, your genetic counsellor will contact you, as agreed, and will be able to discuss the results and what this means for you and your family.
You may find the results unexpected or upsetting. Your genetic counsellor will help prepare you for different outcomes and help you process your reaction to unexpected results.
How long will it take?
This can vary depending on your centre. You may have to wait several months to see a genetic counsellor, and you may also have to wait several months to receive the results of any genetic testing.
What might the results show?
These results might show that you and your partner have the typical number of chromosomes in a typical arrangement. If this is the case, the chance of having another child with trisomy 13 or 18 is estimated to be approximately 1% or dependent on maternal age (NHS England, 2024).
If you or your partner have the typical number of chromosomes in the form of a balanced translocation involving chromosomes 13 or 18, your chance of having another child with trisomy 13 or 18 will be higher. Your genetic counsellor will be able to provide more information about the chance of this.
Because the genetic testing approach used to look for translocations involves looking at all your chromosomes, the genetic testing may reveal another chromosomal difference (such as a balanced translocation involving other chromosomes). Any of these findings which are medically relevant may be discussed during your genetic counselling results appointment.