Congenital lactic acidosis

Congenital lactic acidosis is one of the most common recessive genetic disorders in some regions of Québec:

• Saguenay–Lac-Saint-Jean;
• Charlevoix;
• Haute-Côte-Nord.

A child with congenital lactic acidosis has a deficiency of the enzyme cytochrome c oxidase, which is essential for the human body to function properly. This enzyme plays a key role in producing the energy needed by the cells of the human body. The enzyme’s failure to function properly can affect multiple organs such as the liver, kidneys, muscles and brain.

Nearly 85% of children with congenital lactic acidosis die before the age of five. Those who survive early childhood have a shorter life expectancy and limited autonomy.

The symptoms of congenital lactic acidosis include:

• hypotonia (poor muscle tone) (e.g., the child's body is softer than normal);
• delayed motor development (e.g., the child sits and walks later than is expected for their age);
• lack of energy to grow, fight infections, digest food and cope with stressful life events;
• mild intellectual disability (e.g., the child needs help with learning);
• distinct facial features (e.g., strabismus [crossed eyes]);
• problems coordinating movements;
• trembling associated with certain movements.

Everyone is different. The severity of the disease or its symptoms can vary considerably from one person to another.

There is currently no treatment to cure congenital lactic acidosis. Early treatment for infections and a special diet help improve the quality of life of children with this disorder.

Affected children are cared for by teams of professionals in the health and social services system.

Congenital lactic acidosis can lead to serious complications. They occur when the body has an increased need for energy, for example during high-intensity physical exercise. The child is unable to meet the demand, resulting in a drop in energy and an imbalance in the blood, which becomes more acidic. If the imbalance becomes too great, the child's life may be in danger.

Congenital lactic acidosis is an autosomal recessive hereditary disease.

To find out more, go to the page About autosomal recessive hereditary diseases.

It is impossible to prevent congenital lactic acidosis in newborns who have received a copy of the variant in a gene from each of their biological parents. However, the variant responsible for the disease can be detected in a simple, rapid and inexpensive way.

The Ministère de la Santé et des Services sociaux (MSSS) and the Centre intégré universitaire de santé et de services sociaux (CIUSSS) du Saguenay–Lac-Saint-Jean offer screening tests to identify carriers of this disease.

To find out more, go to the page Carrier screening for autosomal recessive hereditary diseases in people from the Saguenay–Lac-Saint-Jean, Charlevoix and Haute-Côte-Nord regions.

To get help or information on congenital lactic acidosis or advice on delaying or preventing lactic acidosis crises in your child, visit the following links:

• Association de l’acidose lactique du Saguenay–Lac-Saint-Jean (in French only)
• Corporation de recherche et d’action sur les maladies héréditaires (in French only)