Prevalence, characteristics, and clinical outcomes of Huntington's disease in Sub-Saharan Africa: A systematic review and meta-analysis.

BACKGROUND

Huntington's disease (HD) is a rare neurodegenerative disorder with limited epidemiological data in Sub-Saharan Africa. This systematic review and meta-analysis aimed to estimate HD prevalence, describe demographic, clinical, and genetic characteristics, and evaluate clinical outcomes in African populations.

METHODS

Following PRISMA guidelines, we searched PubMed, AJOL, Google Scholar, Cochrane Library, Embase, and Web of Science for peer-reviewed studies on HD in Africa. Eligible studies reported prevalence, characteristics, or outcomes. Prevalence was pooled using a random-effects model (DerSimonian-Laird). Characteristics and outcomes were synthesized narratively. Study quality was assessed with the Newcastle-Ottawa Scale (NOS).

RESULTS

Of 24 eligible studies from sub-Saharan Africa, 8 (10 estimates) were included in the meta-analysis, and all 24 contributed to narrative syntheses. The pooled HD prevalence was 2.81 per 100,000 (95 % CI: 0.45-5.17), with substantial heterogeneity (I2 = 92 %, p < 0.001). Subgroup analyses revealed higher prevalence in South Africa (1.92/100,000) and among Whites/Mixed populations (2.22, 2.17/100,000) versus Blacks (0.01/100,000). Characteristics included mean age at onset of 33-36 years, prevalent chorea (20 studies), cognitive impairment (15 studies), and HTT haplotypes (A1/A2 in Whites/Mixed, B2 in Blacks). Clinical outcomes were sparsely reported, with progressive disability noted in 8 studies but no mortality or survival data. Most studies were moderate quality (NOS 5-6).

CONCLUSIONS

HD prevalence in sub-Saharan Africa is low but varies by region and ethnicity. Limited outcome data highlight the need for standardized reporting. Future research should include North African populations and longitudinal studies to inform clinical management.