In Huntington’s disease (HD), a genetic mutation in the huntingtin (htt) gene results in early loss of the medium sized striatal projection neurons (MSNs) of the striatum, atrophy of striatal volume (Vonsattel et al., 1985), and disruption of functional communication through the basal ganglia pathways, leading to motor, cognitive and psychiatric decline. This evidence concerns the gene HTT and juvenile Huntington disease.