Comprises of several syndromes of bilateral symmetric spongy degeneration of the caudate nucleus, putamen and globus pallidus with characteristics of developmental regression, choreoathetosis and dystonia progressing to spastic quadriparesis. Can be familial or sporadic. The familial form has an insidious onset and a slowly progressive downhill course, while the sporadic form is associated with abrupt neurologic dysfunction following an acute systemic febrile illness such as a mycoplasma, measles or streptococcus infection. Familial disease can be inherited as an autosomal recessive or mitochondrial disorder. [from
SNOMEDCT_US]