MGI:103147Mice homozygous for either the Cra1 or Loa ENU mutation exhibit neonatal lethality with reduced anterior horn cell number, abnormal motor neuron innervation, neuronal inclusions, and abnormal axonal transport. Heterozygotes display motor neuron degeneration and muscle spasms. Homozygosity for the p.K3334N mutation is embryonic lethal. Heterozygosity affects cerebral cortex cell proliferation and migration and leads to small body and brain size, abnormal locomotion and early death.