Can a genetic change be present even without a family history of ALS?

Genetic screening in Germany revealed that 14% of all ALS patients had genetic
mutations in the four most common genes – SOD1, C9orf72, FUS or TARDBP.
Interestingly, only 5.3% of those affected had a familial form of ALS. This
illustrates that genetic mutations can also occur in patients without a family history
. This finding underlines the importance of genetic diagnostics, as
genetic ALS often occurs without any known familial clustering. Genetic
screening can therefore also be helpful in sporadic ALS in order to enable genetic therapy
or participation in clinical trials.