abnormal molar crown morphology, abnormal neuron apoptosis, abnormal neuron differentiation, abnormal peripheral nervous system regeneration, abnormal proprioceptive neuron morphology, abnormal retina ganglion cell morphology, abnormal sciatic nerve morphology, abnormal sensory capabilities/reflexes/nociception, abnormal sensory neuron innervation pattern, abnormal spatial learning, abnormal superior colliculus morphology, abnormal tongue epithelium morphology, abnormal trigeminal ganglion morphology, abnormal tumor necrosis factor level, abnormal vascular wound healing, absent hair follicles, cardiovascular system phenotype, cochlear ganglion degeneration, cochlear hair cell degeneration, decreased Schwann cell number, decreased airway responsiveness, decreased body size, decreased circulating alkaline phosphatase level, decreased exploration in new environment, decreased motor neuron number, decreased muscle spindle number, decreased myocardial infarct size, decreased neuron apoptosis, dilated dorsal aorta, extremity edema, growth/size/body region phenotype, increased neuron number, increased or absent threshold for auditory brainstem response, increased retina photoreceptor cell number, increased susceptibility to age-related hearing loss, increased susceptibility to experimental autoimmune encephalomyelitis, limb grasping, no abnormal phenotype detected, organ of Corti degeneration, perinatal lethality, incomplete penetrance, preweaning lethality, incomplete penetrance, renal/urinary system phenotype, sensorineural hearing loss, small L4 dorsal root ganglion, ulcerated paws