Genetics Questions, Answered by Certified Genetic Counsellors

We can test pregnancies for chromosome conditions, such as Down syndrome. Additionally, we can test a pregnancy for specific genetic conditions if there is a known diagnosis in the family, and that person has had genetic testing. Other conditions would not be tested for in pregnancy unless there was a reason to arrange this testing. For example, if there were specific ultrasound findings. Some diagnoses, such as autism, typically do not have a clear genetic cause, and therefore cannot be checked for in a pregnancy. Targeted genetic testing in a pregnancy is done through an amniocentesis or chorionic villus sampling (CVS).

Genetic counselling is a healthcare service that provides information to individuals and their families about how genetics can impact health. It also involves supporting families as they adapt to new genetic information.

Genetic counselling may help individuals:

• Understand their chances of having a genetic condition
• Understand the chance of having a biological child with a genetic condition
• Understand the features of a genetic condition and how it is passed down (or inherited) in a family
• Make informed decisions regarding family planning, genetic testing, and future health care, based on genetic test results

Usually, genetic counselling is provided by a Genetic Counsellor. Sometimes doctors, nurses, or other health care providers also provide genetic counselling. 

Genetic counsellors often work in a hospital-based genetics clinic. They also work in laboratories, industry, education, and public health settings. 

A formal definition of genetic counselling can be found in this peer reviewed journal article. 

At this time, the government cannot fund Non-Invasive Prenatal Testing (NIPT) for all pregnant women due to the cost. Screening for Down syndrome in pregnancy through tests such as maternal serum screening with or without ultrasound is available to all pregnant women, and additional testing may be offered to those ​​identified to be at an increased risk, based on provincial guidelines. You can speak to your health care provider to determine if you are eligible.

No, not everyone with a hereditary cancer condition will develop cancer in their lifetime. For example, in a family that has “hereditary breast cancer”, there will likely be family members who live a long lifetime, and never develop any type of cancer.

People who have a mutation in a hereditary cancer gene have an increased risk to develop one or more types of cancer compared to other people who find out that they don’t have that mutation.   

The likelihood of being diagnosed with cancer depends on several factors, including,  the gene involved, the person’s biological sex, environmental factors, and whether the person has undergone risk-reducing management (example: a mastectomy or removal of the breast tissue to reduce risk for breast cancer).  

People who receive a positive genetic test result often have genetic counselling, so they can better understand their cancer risks and future cancer screening and medical management options.

There are many topics that will be discussed when meeting with a genetic counsellor. A genetics appointment might also include a physical exam, performed by a Medical Geneticist (doctor). If genetic testing is offered, it will most often be done using a blood or saliva sample. 

Part of a genetics appointment includes gathering accurate personal health information and family history. Common questions asked by a genetic counsellor might include:

• Current and past medical history.
• Family health history information.  Usually, a genetic counsellor will ask questions about at least three generations of your family.  It is useful to know the name of any conditions diagnosed in relatives, as well as their age at the time of diagnosis.
• Your partner’s medical and family history, if relevant.

During an appointment, a genetic counsellor may discuss:

• The features, signs, and symptoms of a genetic condition.
• How a genetic condition is passed down (inherited) in a family.
• The likelihood of having a genetic condition.
• The chance of having a biological child with a genetic condition.
• Genetic testing options.
• The benefits and limitations of genetic testing.
• The possible results from a genetic test.
• Available screening, surveillance, and/or treatment options.
• Available resources related to a genetic condition.

To meet with a genetic counsellor there must be an increased risk for a genetic condition compared to the general population. Some reasons to see a genetic counsellor include family history of a genetic condition, biological parents are carriers of genetic conditions, ultrasound findings, including some soft markers, or high-risk prenatal screening results.