Fig. 1

Distribution of differentially regulated features and ALS patient phenotypic variants: (a) Principal component analysis (PCA) using scores plots before feature selection (colour codes: fast-early: yellow; fast-late: green; slow-early: red; slow-late: brown). The disease stage dimension is the main contributor to the separation in the first component (35.86%) and the rate of disease progression is the main contributor to the separation on the second component (15%). b PCA loadings plot generated with data derived from regulated features shows a more significant separation in the first compared to second component (40.6% and 17.5% respectively). c Volcano plot showing significantly regulated features comparing fast and slow progressing ALS patients in the early time point (cross-sectional study). d Volcano plot showing significantly regulated features comparing early and late time points for the slow progressing ALS patients (longitudinal study). Volcano plots agree with PCA showing a more significant difference between early and late time points when compared to fast versus slow disease progression