Differences in duration of Huntington's disease based on age at onset

Objectives-Data from a sample of 2494 patients affected with Huntington's disease (HD), collected as part of the National Research Roster for Huntington Disease Patients and Families, were examined to determine if there was a relation between age at onset and duration of illness. Methods-Sufficient data for inclusion in analysis was available from 2068 patients, of whom 828 were deceased and 1240 were living. The median duration of disease was 21.4 years with a range of 1.2 to 40.8 years. Patients were categorised into one of four groups based on their age at onset. Results-Significant differences in duration based on the age at onset were found (p<0.025), with juvenile and late onset patients with HD having shorter duration of illness compared with those with an onset between 20-49 years. Conclusions-Duration of disease is influenced by the age at symptom onset with juvenile and late onset patients having the shortest duration.