Carrier screening for genetic diseases

Offered in collaboration with Genolife, the carrier screening test is available to individuals who are interested in learning about their possible risks to have a child with an inherited disease, for example cystic fibrosis. This test can be personalized depending on an individual’s needs and primary concerns and includes genetic counselling.

The carrier screening test can be done before or during a pregnancy and can screen up to 301 genes. The genetic diseases that can be included have different impacts on those who are affected. Some of them are associated with disabilities, with various health complications or have limited or no treatment options. Through early detection, the lives of these individuals can be greatly improved through timely and appropriate interventions. When a couple is identified as being at risk, our genetic counsellor will discuss in detail the specific condition, the risks and the reproductive options.

This test is also available for people with a family history of genetic disease or for those with an increased risk related to their ethnicity. In addition, the test can analyze genes associated with both autosomal recessive and X-linked inheritance.

Certain individuals are at higher risk for a genetic disease, including:

• Individuals from the Saguenay-Lac-St-Jean, Charlevoix and Haute-Côte-Nord regions of Quebec
• Individuals of Ashkenazi Jewish origin
• Individuals from the Mediterranean region

Autosomal recessive inheritance

Each of us is a carrier of at least one genetic disease. A carrier has one copy of a gene that is modified (has a pathogenic variant or a mutation) and the other copy of the same gene is functional. A carrier usually has no symptoms or family history of this disease. When both parents are carriers of the same disease, their children each have a 25% risk (1/4) of having the disease.

Examples of autosomal recessive diseases: cystic fibrosis, Tay-Sachs disease, tyrosinemia and spinal muscular atrophy

X-linked inheritance

These diseases are transmitted by a carrier mother and it is usually their sons who are affected.

Examples of X-linked diseases: Fragile X syndrome, Duchenne muscular dystrophy