Some individuals or couples who are planning pregnancies are interested in knowing whether they have an increased risk of having children with specific genetic diseases. Preconception genetic carrier screening is available to assess this risk. A genetic carrier is an individual who has an abnormality (known as mutation or variant) in one of the two copies of genes. In most cases, the genetic carrier is normal and does not show any signs of having the disease. However, if he/she ends up having children with another genetic carrier, there is an increased risk of having children with the condition.

The decision on whether to do genetic testing is a personal one. It is important that you understand the limitations of preconception genetic carrier screening before you make a decision to proceed with it. No genetic carrier screen is able to cover all genetic diseases. Our clinic is currently using a test from a genetic laboratory called Invitae and the test covers 302 genetic diseases. A negative screen (results that do not detect any carrier state for any disease) only provides us with information on the specific diseases covered by the screen. Despite a negative screen result for a specific disease, there is still a small residual risk that an individual is indeed a carrier.

Couples who are thinking of completing the carrier screening may decide to do the test on only one or both partners simultaneously. If they decide to have the test done on only one partner, they can wait until the result is back first. If the screen is positive for any specific genetic disease, they can then decide to proceed with testing the second partner.

Individuals who are planning on donor sperm or donor egg treatment may also want to do the preconception genetic carrier screening so they can avoid choosing a donor who is a carrier for the same genetic disease as themselves. It is important for one to realize that your donor of interest may have previously completed genetic carrier screening and may have already been identified to be a carrier of a specific genetic disease. If such is the case, please let your physician know of the disease of concern as it may not be one that is covered under the Invitae carrier screen. In such case, we will refer you to a genetic specialist for genetic counselling on the disease.

Preconception genetic carrier screening is not currently covered by Alberta Health Care. Please contact our clinic if you would like information on the cost of having the test through our clinic.

We hope you find this information helpful. Please do not hesitate to contact our clinic if we can provide you with any further assistance.

The decision to undergo specific testing would depend on your own individual situation and is best discussed with your family physician, midwife or obstetrician responsible for your prenatal care. Each test has its own unique indication, risks, limitations and optimal timeframe for the test to be conducted.

For further information on the Harmony test, please speak to your RFP physician or refer to the Harmony Prenatal Test website.