Figure 1.

The phenotypic spectrum of amyotrophic lateral sclerosis (ALS) genetics. (A) Forty-six ALS-related genes are arrayed along axes that depict two major phenotypic aspects: the extent to which corticospinal versus lower motor neurons are involved (y-axis) and the overlap with frontotemporal dementia (FTD) (x-axis). The diameters of each gene approximate their relative frequencies. (B) The phenotypic overlap of ALS genes with hereditary spastic paraplegia (HSP), frontotemporal dementia (FTD), mitochondrial disease, and lower motor neuropathies (LMN) is shown.