Of the eleven children who were clinically diagnosed with Huntington's disease who did not have a repeat expansion, five presented with movement symptoms alone, two with chorea, two with involuntary movements, and one with tremors. Three of the children presented with rigidity; two also had declining school performance and the other had EEG abnormalities. One child presented with psychiatric symptoms. Another had Pelizaeus-Merzbacher disease, another rare movement disorder. Another child presented with Tourette's syndrome and developmental delay. Six of the children had no known history of HD in the family.
Of the fifteen children who did have the CAG expansion and became symptomatic in the first decade, all had an affected parent. Twelve had CAG repeats of 80 or more and two of the following symptoms: declining school performance, seizures, oral motor dysfunction, rigidity, and gait disorder. There were three children who presented with one symptom and who had CAG epansions less than 80 repeats.
The eighteen children with CAG expansions who became symptomatic at ten or older presented with a more diverse groups of symptoms. Only one fit the adult pattern of symptoms. Some presented with rigidity and declining school performance and some with severe behavioral symptoms. Another group had lifelong cognitive problems with onset associated with behavioral then movement problems.