Infantile Neuroaxonal Dystrophy (INAD) is an extremely rare neurodegenerative disorder, characterized by psychomotor regression and hypotonia, which progresses to spastic tetraplegia, visual impairment, and dementia. The underlying pathophysiology of the condition is an abnormal build-up of toxic substances in nerve axons. The most common, classic form of the disease has its onset between six months to three years after an affected child's birth, when it presents with hypotonia progressing to spasticity, progressive psychomotor delay, and symmetric pyramidal tract signs. Children may also show strabismus, nystagmus, optic atrophy, seizures, deafness, and dementia. Distinctive facial features seen in patients include a prominent forehead, a small nose or jaw, and large, low-set ears. Abnormal accumulation of iron is seen in the basal ganglia, a feature seen in other neurodegenerative disorders, such as Alzeimer's and Parkinson Disease. Disease progression is very rapid, and the child quickly loses touch with its surroundings. Death occurs between the ages of 5 and 10 years. The atypical form of the disease has its onset as late as in the early teens. This form is more varied, with a slower rate of disease progression, but ends, like the classic form, with fatal neurologic deterioration between the ages of 7 and 12 years. The disease is extremely rare, estimated to occur at proximately 1 in every 1,000,000 individuals.
