ALS and Who It Affects
Researchers are currently studying ALS (amyotrophic lateral sclerosis) and who it affects. The link between ALS and who it affects is associated with familial ALS and ALS that occurs at random with no associated risk factors. In the United States, approximately 20,000 people have ALS, and an estimated 5,000 people are diagnosed with ALS each year.
In the United States, approximately 20,000 people have ALS (amyotrophic lateral sclerosis), and an estimated 5,000 people are diagnosed with ALS each year. ALS is one of the most common neuromuscular diseases worldwide, and it affects people of all races and ethnic backgrounds. Although ALS usually strikes people between the ages of 40 and 60, people who are younger or older than these ages can also develop the disease. ALS tends to affect more men than women.
In 90 percent to 95 percent of all ALS cases, the disease occurs at random with no clearly associated risk factors, and about 5 percent to 10 percent of all ALS cases are inherited. The familial form of ALS usually results from a pattern of inheritance that requires only one parent to carry the gene responsible for the disease.
(Click Familial Amyotrophic Lateral Sclerosis for more information about inheriting ALS.)
Approximately 20 percent of all familial cases result from a specific genetic defect that leads to mutation of the enzyme known as superoxide dismutase 1 (SOD1). Research on this mutation is providing clues about the possible causes of motor neuron death in ALS. However, not all familial ALS cases are due to the SOD1 mutation, which means that other unidentified genetic causes clearly exist.