Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, because this baseball player was the first to be diagnosed, is a progressive neurodegenerative disease that affects nerve cells in the brain. Specifically, the nerve cells affected are the motor neurons of the cerebral cortex (upper motor neurons), brainstem and spinal cord (lower motor neurons).
The involvement of the motor neurons characteristic of the disease causes progressive loss of movement, as well as respiratory failure due to atrophy of the muscles of the thoracic area.
It is, in most cases, a late-onset disease, with the average age of onset of the disease being around the fifth decade of a person’s life.
Early symptoms include muscle spasms, cramps, stiffness or weakness during the early stages of the disease. As the disease progresses and intermediate stages are reached, the disease usually presents with speech disorders, as well as dysphagia or difficulty swallowing, progressive loss of movement and weakness, to the point of requiring a wheelchair to move around. Finally, if the disease progresses, atrophy reaches the muscles of the thoracic area, which can lead to respiratory failure and death of the sufferer.
The role of genetics in ALS
To answer the question of whether amyotrophic lateral sclerosis is hereditary, we can say that the heritability of ALS is estimated to be around 40-45%, which means that both genetic and environmental factors are involved in its etiopathogenesis.
Among the genetic factors that play a relevant role in the development of ALS are the SNPs that we study in our DNA test.