Who can get ALS?

Why do people develop ALS?

A small number (10 per cent or less) of people with ALS have familial (or hereditary) ALS. The rest (90% or more) of ALS cases are random (or sporadic). As the name “random” implies, anyone can develop ALS, including young adults and the elderly.

On average, the first symptoms of ALS begin to show up in the mid- to early senior years. It is most commonly diagnosed between the ages  of 40 and 70. ALS is diagnosed in both men and women of all ethnic and socio-economic groups.

Risk factors

There is no one thing that causes ALS. Rather, ALS is recognized as having multiple interacting causes that are likely based on changes in people’s genes, and possibly contribution of environmental factors. A number of genes have been identified as playing a role in the development of ALS. Through research, we are learning more about ALS and the multiple factors that may trigger its development.

• Genetics: There are several genetic mutations linked to ALS. These include SOD1, C9ORF72, TDP-43 and FUS.
• Age: The risk of developing ALS increases with age.
• Heredity: Most people with the familial form of ALS have a 50 per cent chance of passing the disease to each child.
• Smoking: Smoking is the only environmental factor to be recognized as having a direct influence on increasing the risk of developing ALS.

_{Content adapted from the ALS Canada Website, as well as the ALS Guide, which was published in 2019 as a joint project of ALS Societies across Canada.}