NIPT (also called NIPS) is a prenatal screening test that screens for extra or missing copies of chromosomes 13, 18, 21 and the sex chromosomes. PGT-A screens for extra or missing copies all chromosomes, including 13, 18, 21 and sex chromosomes. After PGT-A, your pregnancy is at very low risk for a chromosome condition, but since PGT-A isn’t a perfect test, you can consider NIPT if you want further reassurance. If there are any specific ultrasound findings, NIPT may be suggested by your doctor.

Most likely you have been offered something called “PGT-A,” which is a type of genetic testing anyone can do on their embryos. It stands for Pre-implantation Genetic Testing for Aneuploidy, and it checks the embryo for extra or missing chromosomes before pregnancy. PGT-A is often used to help pick embryos that are more likely to lead to successful pregnancies. But PGT-A does not guarantee a pregnancy or healthy baby. There are many things it can’t detect.

In some cases, a specialized type of genetic testing can be done on embryos. If you or your partner have a specific disease-causing change (i.e. mutation) in one of your own genes, or a rearrangement in your chromosomes, you may be eligible for PGT-M or PGT-SR. Ask your doctor for more information, and to find out if this applies to you.

We all have differences in our genes. Most of those differences do not cause us any harm and simply lead to our individuality. However, some of the differences in genes can lead to health conditions. We call these changes harmful or pathogenic. In some cases, the lab will be unable to say with certainty if a genetic difference will or will not be harmful. We call these uncertain results variants of uncertain significance (VUS). The lab may be unable to clarify due to many factors, but typically there is not enough information in the genetics literature to say with certainty if your genetic difference is harmful or not.  In a few years, new information may be available to clarify if the change is related to the health issues that you have or that is present in your family and therefore it may be helpful to recontact your genetics team.

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. 

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.

Yes. A mutation in a hereditary breast cancer gene can be inherited from either a person’s mother or father. It is a myth that risk for breast cancer cannot be passed down from the father’s side of the family.

This means it is important to review the family history of breast cancer on both sides of the family during a hereditary breast cancer risk assessment. 

Men can develop breast cancer, however, the risk for a man with a mutation in a hereditary breast cancer gene to develop breast cancer is significantly lower than a woman with a mutation in the same gene. 

Everyone will have their own personal reasons for wanting to find out whether they have a hereditary cancer condition. Genetic testing is used to confirm whether someone has a hereditary cancer condition or not.
 

Some common reasons for wanting genetic testing when it is offered after a cancer diagnosis include:

• It may help provide an explanation for why a person developed cancer.
• It may help a person’s oncologist determine what is the best treatment plan, and whether a person is eligible for a specific medication.
• It may provide more precise information about the chance of developing a second, and unrelated cancer during one’s lifetime.
• It may help a person decide about future cancer screening and prevention options. For example, risk reducing surgery to remove breast tissue for those known to have a high lifetime risk of breast cancer.
• It may help other family members understand their chance of developing cancer, as well as their options for screening and prevention.

Some of the common reasons to want genetic testing for those who have never had a cancer, but know of a hereditary cancer condition in their family, include:

• It may provide more information about lifetime cancer risks.
• It may help determine cancer screening and prevention options.
• It may help other family members understand their chance of developing a cancer and access screening or preventative options.

While there are many reasons people may want to know if they have a hereditary cancer condition, there are also reasons why people may not want to know this information.  There are also many valid reasons to delay genetic counselling and/or genetic testing to a later time in one’s life. Meeting with a genetic counsellor will allow you to explore which option is best for you at this time.

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.

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.

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.

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.

In Canada, an appointment with a genetic counsellor is often covered by provincial health systems for individuals who meet eligibility criteria.  Eligibility can vary from centre to centre. 

Genetic counselling appointments through a private clinic are typically not covered by provincial health insurance plans.  Some extended health insurance plans may cover a portion of a fee for genetic counselling and/or genetic testing.  Some genetic testing companies offer accompanying genetic counselling services.

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).

Genetic testing is a powerful tool used to look for genetic changes (alterations in our DNA) that may impact health. These genetic changes are called DNA variants.  DNA variants may provide useful information about an individual’s health, or the health of their relatives.  

Genetic testing might find a genetic cause for a previously diagnosed condition, or it might uncover the chance of developing a health concern in the future. Sometimes genetic test results can help guide future health screening, suggest preventative options, or guide best treatments.

When genetic testing is done, it might report a change in a gene that makes that gene work incorrectly.  This type of alteration is called a “pathogenic variant”.  Genetic testing might also reveal that no gene variants were found in a gene, or genes, of question.  Sometimes genetic testing reports a variant that is uncertain, and the genetics team can’t confirm whether that variant causes a health condition, or whether it may be a harmless and insignificant genetic change.

As we learn more, the information available about genetic testing and genetic test results may change.  It may be important to keep in touch with your genetics health care providers.

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. 

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.

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).

Your genetic counsellor will ask you questions about your pregnancy, as well as your family history. They will review genetic concepts, and review information about the reason you were referred (e.g., a positive screen, an ultrasound finding, or a family history of a genetic condition). You will be offered appropriate testing, if applicable, and you will be supported throughout the process. In some areas, follow up is done by a team of clinicians and nurses.

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.

Your doctor will offer screening for various conditions during your pregnancy. This screening will include a combination of a blood test, mother’s age at delivery and possibly an ultrasound. All of this information helps evaluate the chance that the pregnancy may have Down Syndrome (Trisomy 21). A positive (or high risk) result means your pregnancy is at an increased risk for Trisomy 21. This does not mean that the baby definitely has Trisomy 21. However, your positive screen means that there is a higher chance that this may happen and therefore you are eligible for some additional testing if you wish to clarify if this is the case or not. Talk to your family doctor, obstetrician, or midwife about next steps, such as follow-up testing or a referral to a genetic counsellor.