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. 

If there is a known hereditary cancer condition in a family, and a person tests negative for the specific mutation seen in their relatives, it means they do not have the increased risk for cancer associated with having that gene mutation.  

However, no genetic test can eliminate the risk for a person to get cancer. This is because most of the time cancer occurs sporadically, influenced by risks related to a complex combination of increasing age, environmental factors, and lifestyle choices. A person who is negative for the hereditary cancer condition known in their family can still develop cancer sporadically, like other people in the general population. 

A person’s residual risk for cancer after genetic testing should be discussed with their healthcare provider, as there are multiple factors to consider.

Genetic counsellors obtain a Master’s degree in Genetic Counselling, after having completed a Bachelor degree. Genetic counsellors working in Canada are certified by either the Canadian Board of Genetic Counselling (designated CCGC) and/or by the American Board of Genetic Counseling (designated CGC).

Hereditary cancer is caused by a change in a gene (called a mutation or variant) which is passed down from generation to generation in a family. Family members who inherit the hereditary cancer gene mutation face a higher lifetime risk for certain types of cancer, depending on the gene involved. Families with a hereditary cancer condition (or syndrome) may have a clustering of certain types of cancer in closely related family members, and there may be relatives with more than one cancer during their lifetime.  In these families people often develop cancer at a younger age than usual. 

It is important to note, most cancer is not hereditary, but happens by chance and is influenced by age, environmental factors, and lifestyle choices.

Our genome, or DNA, is how we refer to the information contained in our cells which provides the ‘recipe’ to create an individual. Exons are the parts of our DNA that provide instructions to create proteins, and they make up  around 1% of our DNA. Proteins are important for our cells to carry out their functions (E.g., helping us grow, digesting our food, keeping our hearts beating). Together, all of the exons in our genome are known as the exome, and the method of sequencing them is known as whole-exome sequencing (WES). This approach to testing looks for genetic changes in exons of all genes. WES is thought to be an efficient method to identify possible disease-causing genetic changes (i.e. pathogenic or likely pathogenic variants, also called mutations) because most known variants that cause disease occur in exons. 

Yes, some genetic testing is offered regardless of known family history information.  Also, if you have features of a genetic condition, there may be options for genetic testing to clarify a diagnosis.

For those who do not know about the health of their biological relatives, the results of genetic testing can sometimes be used to provide information about future health care options.