<prompt> The hyperkinetic features of the Huntingtons disease are due to the loss ofNigrostriatal dopaminergic systemIntrastriatal cholinergic systemGABA-ergic and cholinergic systemIntrastriatal GABA-ergic and cholinergic system  <response>: It is a genetic disease of nervous system inherited as an autosomal dominant disorder usually occurring between 30 and 50 years of age. Site of lesion : There occurs damage to GABAergic and cholinergic neurons of striatum caudate and putamen that project to pallidum The loss of GABAergic pathway to the external pallidum releases inhibition, permitting the hyperkinetic features of the disease to develop. It affects 5 out of 100,000 people worldwide Ref: Ganongs Review of Medical Physiology 26th edition pg no.566 