Atypical Presentations of Huntington Disease-like 2 in South African Individuals

Heena Narotam-Jeena; Mark Guttman; Ludo van Hillegondsberg; Riaan van Coller; Amanda Krause; Jonathan Carr

doi:10.1002/mdc3.14052

Atypical Presentations of Huntington Disease-like 2 in South African Individuals

Mov Disord Clin Pract. 2024 May 9. doi: 10.1002/mdc3.14052. Online ahead of print.

Authors

Heena Narotam-Jeena¹, Mark Guttman², Ludo van Hillegondsberg¹, Riaan van Coller³, Amanda Krause⁴, Jonathan Carr¹

Affiliations

¹ Division of Neurology, Department of Medicine, University of Stellenbosch, Cape Town, South Africa.
² Centre for Movement Disorders, Markham Ontario, Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
³ Department of Neurology, University of Pretoria, Pretoria, South Africa.
⁴ Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.

PMID: 38725192
DOI: 10.1002/mdc3.14052

Abstract

Background: Huntington disease-like 2 (HDL2) is a neurodegenerative disorder, affecting only individuals of African ancestry. Full penetrance occurs in individuals with 40 repeats or more.

Objective: To describe the phenotypic variability of HDL2 in a group of mixed ancestry individuals from South Africa.

Methods: Eight patients were assessed with analysis of repeat size and magnetic resonance brain imaging. We applied the Unified Huntington's Disease Rating Scale (UHDRS), but in deceased patients (4), this was estimated from video material.

Results: Cognitive domains were more severely affected than motor; UHDRS motor scores were notable for bradykinesia, and to a slightly lesser extent, for rigidity and dystonia; a single patient had marked chorea. Repeat lengths ranged from 45 to 63 (median, 52).

Conclusion: This South African group of mixed ancestry HDL2 individuals presented with severe cognitive and behavioral impairments, with lesser degrees or absence of chorea. This presentation is possibly related to large repeat sizes.

Keywords: HDL2; Huntington; chorea.