No Evidence of Early Developmental Delay in Juvenile-Onset Huntington's Disease Patients

Background: Previous studies suggest that early developmental delay is a common feature of Juvenile-Onset Huntington's disease (JOHD), with highest incidence in those with very high CAG repeats (> 80). However, all reports of developmental delay in JOHD are exclusively based on retrospective review of medical charts. Comprehensive assessment of birth history metrics may provide better insight into the question of early life development in JOHD.

Objective: To explore the prevalence of prematurity, birth complications, low birth weight and developmental delay in patients with JOHD in comparison to control participants.

Methods: Parents of patients with JOHD and gene-non-expanded (GNE) control participants from Kids-HD (n = 104) and Kids-JOHD (n = 34, 24% with CAG > 80) studies completed a comprehensive birth history questionnaire. Answers focused on prematurity, birth complications, and birth weight, and along with reports of early developmental milestones, were compared between groups.

Results: There were no statistically significant differences in prematurity, birth weights, birth complications, or motor and verbal developmental milestones between JOHD patients and GNE controls (all P values > 0.1). Furthermore, stratifying JOHD patients by CAG expansion (low vs. high) also showed no significant differences (GNE vs. low or GNE vs. high).

Conclusions: These findings support the notion that JOHD does not manifest as developmental delay before motor symptom onset and highlight a new framework to understand the course and nature of the disease.