Huntington's disease in MENAT: systematic review and meta-analysis of prevalence, clinical features, and genetics

To estimate prevalence and describe clinical and genetic features of Huntington's disease (HD) in the Middle East, North Africa, and Turkey (MENAT).

We conducted a PRISMA-guided systematic review and meta-analysis of EMBASE, PubMed, and Scopus from inception to October 2024. All study designs reporting HD in MENAT countries were eligible. Extracted data included demographics, clinical features, CAG repeat lengths, and prevalence. Random-effects models generated pooled estimates.

Seventy-five studies (1124 individuals) were included. The pooled literature-derived prevalence was 0.17 per 100,000 (95% CI, 0.12-0.21; I² ≈ 99%), well below global estimates and highly heterogeneous across countries. Highest national estimates were Oman 4.66, Tunisia 1.27, and Turkey 0.73 per 100,000; several countries (e.g., Sudan, Lebanon, Afghanistan) reported only isolated cases (< 0.01 per 100,000). Mean age at onset was 43.3 years in adults and 13.4 years in juvenile cases. Mean CAG repeat length was 45.1 in adults and 67.2 in juvenile-onset HD; overall mean 48.6.

HD appears underreported in MENAT, with prevalence far below global figures, likely reflecting underdiagnosis and limited genetic testing capacity. Priorities include expanding access to confirmatory testing, establishing national registries, and enhancing clinician awareness to improve detection, care, and regional epidemiologic precision.