An animal model for motor neuron dysfunction in disease, e.g., amyotrophic lateral sclerosis (ALS), comprising a genetically modified non-human animal that comprises a genetically modified DR6 allele and exhibits normal phenotypes at birth and for a few weeks or months after birth. However, as the non-human animal ages, it develops motor neuron dysfunction that presents as one or more ALS-like symptoms, which may progress rapidly after onset. Methods of identifying candidate agents that may be used to prevent, delay or treat ALS are also provided.
