“…To date, clinical characteristics such as site of onset, respiratory status, ALS Functional Rating Scale (ALSFRS) scores (Cedarbaum et al, 1999) and C9orf72 phenotype status (i.e. a disease-causing repeat expansion mutation in ALS (DeJesus-Hernandez et al, 2011, Renton et al, 2011)) are shown to have some predictive power for prediction of survival (Chiò et al, 2009, Elamin et al, 2015, Scotton et al, 2012, Wolf et al, 2014, Wolf et al, 2015). Prognosis based on these markers, however, often remains too uncertain to be implemented in clinical practice (Elamin et al, 2015) as motor neuron loss might already occur before clinical weakness can be measured (Simon et al, 2014).…”