Determinants of Onset of Huntington's Disease with Behavioral Symptoms: Insight from 92 Patients.

Background: Huntington's disease (HD) is a genetically mediated neurodegenerative disorder characterized by presence of involuntary movements, behavioral problems and cognitive dysfunctions. Though few patients with HD may have behavioral symptoms at onset of the disease, studies comparing patients with behavioral symptoms at the onset of HD with those having motor symptoms are sparse.

Objective: Objective of this study is to determine the differences in the demographic and genetic characteristics of patients with behavioral symptom at the onset of HD from those with motor symptoms.

Methods: A chart review of 92 patients with HD who had attended the neurology outpatient clinics of National Institute of Mental Health and Neurosciences, India was done. Demographic and genetic characteristics of HD patients with onset of the disease with initial behavioral symptoms (HD-iB) were compared with patients with onset of the disease with initial motor symptoms (HD-iM).

Results: The principal findings in our study were (i) higher proportion of patients with HD-iB had a positive family history of HD, (ii) maternal inheritance of HD was more frequent among those with HD-iB, and (iii) There is no significant difference between the CAG repeat length between HD-iB and HD-iM groups.

Conclusion: Presence of family history of HD especially inheritance of HD from mother may be associated with behavioral symptoms at the onset of HD. CAG repeat length in patients with HD-iB does not differ from those with HD-iM.