Five diseases are particularly common in the Charlevoix and Saguenay Lac-Saint-Jean (SLSJ) regions:
- Congenital Lactic Acidosis
- Hereditary Motor and Sensory Neuropathy
- Recessive Spastic Ataxia of Charlevoix Saguenay
- Cystic Fibrosis
The carrier frequency is similar for each of these diseases, about one individual in 20. The genes associated with these diseases are known and when tested have a 93% to 99% detection rate in French Canadians. At this time, only those individuals who already have a known case in their family or their partner is known to be a carrier can turn to the Canadian Public Health system for screening. However, it is possible to get genetic screening tests performed at Procrea Fertility to find out your carrier status.
Tyrosinaemia (type I) is a hereditary metabolic disorder characterized by the lack of the enzyme needed to break down tyrosine, an amino acid found in proteins in our diet. Failure to properly break down tyrosine leads to the accumulation of toxic metabolic waste and brings liver and kidney damage.
Congenital Lactic Acidosis
Congenital lactic acidosis (also known as COX deficiency or French Canadian type Leigh syndrome) is also a hereditary metabolic disorder caused by the lack of an enzyme necessary to produce energy in the liver and the brain. On average, affected children die before the age of 6, generally following an acute lactic acidosis episode. At this time, there is no treatment for the disease.
Hereditary Motor and Sensory Neuropathy (ACCPN)
Hereditary motor and sensory neuropathy (with or without agenesis of the corpus callosum), also known as Andermann or Charlevoix syndrome, is a hereditary neurological disease with symptoms surfacing in the first year of life: lack of muscle tone and slow motor development accompanied by delayed mental development (light to moderate). At adolescence, progressive peripheral nerve deterioration results in a loss of the ability to walk as well as progressive scoliosis. Their life expectancy is lower than the general population. Although there is no cure for the disease, medication and treatment can alleviate several symptoms.
Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS)
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (or ARSACS) is a hereditary neuromuscular disease. The affected child begins to walk later than normal, stumbles more often and the disease is usually diagnosed at 10 years of age. Mental abilities remain normal. Medication and treatment can relieve some of the symptoms.
It should be noted that Cystic Fibrosis is common not only in the Charlevoix and Saguenay Lac-Saint-Jean regions, but everywhere else in Quebec. The carrier frequency is about 1 in 15 people in the Charlevoix and SLSJ regions and 1 in 25 everywhere else in Quebec.