A genetic disorder involving progressive neurologic degeneration with the accumulation of iron in the brain. The gene for the disease is on chromosome 20. The syndrome was first described by Julius Hallervorden and Hugo Spatz in 1922 in 5 sisters who showed increasing dysarthria (trouble speaking) and progressive dementia and, at autopsy, brown discoloration of specific parts of the brain (the globus pallidus and substantia nigra). The disease is characterized by progressive rigidity, first in the lower and later in the upper extremities. Involuntary movements of choreic or athetoid type may precede or accompany the rigidity. Both involuntary movements and rigidity may involve muscles supplied by cranial nerves, resulting in difficulties in articulation and swallowing. This disorder affects the muscular tone and voluntary movements progressively, making coordinated movements and chewing and swallowing almost impossible. Mental deterioration, emaciation, severe feeding difficulties, and visual impairment occur commonly in the late stages of the disease. The disease has its onset in the first or second decade of life and the average survival time after the diagnosis is made 11 years. Death usually occurs before the age of 30 years. The diagnosis has usually been made postmortem. However, magnetic resonance imaging (MRI) alterations in the basal ganglia of the brain now permit diagnosis during life in someone who has an affected sibling and is therefore at high (25%) risk for the disease. Other names for this disorder include neurodegeneration with brain iron accumulation (NBIA) and late infantile neuroaxonal dystrophy.