Black patients with Huntington disease (HD) who were part of a retrospective cohort study tended to have more severe symptoms at baseline than other racial groups studied according to an article published in Movement Disorders.

The Black patients tended to have more impairment on the total functional capacity (TFC) scores, lower processing speed and visual attention with the Symbol Digit Modalities Test (SDMT), had lower cognitive performance on the Stroop Word Reading (SWR), and had more severe total motor scores on the Unified Huntington’s Disease Rating Scale (UHDRS) than the other race groups.

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Black study participants had significantly lower (more impaired) TFC scores when compared to White (P =0.0202), Asian (P =0.02), and Hispanic (P =0.0237) participants. SDMT scores for Black participants were also significantly lower than White (P =0.0014) and Asian (P =0.0268) participants.

Cognitive performance measured through the SWR was also significantly lower for the Black group compared to the White (P =0.0006) and Asian (P =0.0082) groups. Hispanic participants also had lower scores on the SDMT and SWR tests compared to White participants (P =0.0163 and P =0.0045, respectively).

Total motor scores on the UHDRS were more severe at baseline for the Black participants than for the White (P =0.0003), Asian (P =0.0152), and Hispanic groups (P =0.0372). No difference was observed between the racial groups in terms of Problem Behaviors Assessment scores. While Black participants tended to have lower baseline values, no significant difference was observed in clinical progression between the racial groups over time (up to 2000 days since baseline).

“We see clear differences in baseline clinical status in Black participants in the Enroll-HD trial. These results suggest that there may need to be improvements in recruitment and retention of Black HD sufferers in clinical research and further educate the diverse population of HD,” the authors wrote.

A total of 208 White, 208 Hispanic, 104 Black, and 104 Asian participants were included in the age and cytosine–adenine–guanine age product score-matched cohort. While the data set is global, all of the Black participants were from North America. The Black cohort had the highest percentage of education at high school level and beyond (96%) and also had the highest percentage of chorea medication (28.8%).


Buchanan DA, Brown AE, Osigwe EC, et al. Racial differences in the presentation and progression of Huntington’s disease. Mov Disord. Published online August 10, 2023. doi:10.1002/mds.29536