Familial ALS

Familial ALS is inherited in a genetically dominant pattern. This form of ALS is seen in only five to 10 percent of ALS cases. A mutation for the gene for Superoxide dismutase (SOD1) on chromosome 21 was found to be the cause of familial ALS in 20 percent of these patients, however the cause in the remaining 80 percent is unknown.

Since genetic mutation is inherited in an autosomal dominant pattern, the offspring of someone with familial ALS will have a 50 percent chance of being diagnosed with this disease.