Figure 3. Mean Ages at Onset for Motor and Psychiatric Symptoms at Different CAG Repeat Lengths.

Shown are the mean ages at symptom onset as recorded by the Huntington Disease Clinical Characteristics Questionnaire for apathy (n = 2,739), cognitive impairment (n = 3,069), depression (n = 3,399), irritability (n = 3,117), and motor symptoms (n = 4,889).