The range of neurological presentations is broad and includes, but is not limited to: epilepsy (eg, familial adult myoclonic epilepsies (FAME)); ataxia (eg, SCAs, CANVAS and Friedreich’s ataxia); cognitive impairment (eg, C9orf72-associated frontotemporal dementia and ALS); movement disorders (eg, Huntington’s disease, X-linked dystonia-parkinsonism); learning difficulty (eg, fragile X syndrome) and neuromuscular disorders (eg, myotonic dystrophy types 1 and 2, oculopharyngeal muscular dystrophy (OPMD)). Here, C9orf72 is linked to amyotrophic lateral sclerosis.