The LRRK2 gene, particularly its G2019S variant, has emerged as one of the most frequently reported genetic mutations associated with Parkinson’s disease (PD) across diverse populations. Global epidemiological data underscore the pronounced ethnic variability in its prevalence: approximately 13% among Ashkenazi Jews, up to 30% in Arab-Berber cohorts, and variable rates among Spanish populations, ranging from 6.1% to 41% in sporadic PD cases. In contrast, LRRK2 mutations are infrequent in Asian populations, reflecting distinct genetic backgrounds and founder effects. The G2019S variant has also been observed in 5.6% of North American families with familial PD, 6.6% in autosomal dominant cases from Southern Europe and Latin America, and 1.7% of British patients with sporadic PD. In the Moroccan context, the relevance of screening for the G2019S mutation lies in its potential utility as a predictive and diagnostic biomarker. Carriers of this mutation often present with a clinically milder form of PD, marked by slower disease progression and relatively preserved cognitive function. This genotype-phenotype correlation can facilitate more accurate patient stratification and personalized therapeutic strategies. The present study aims to estimate the prevalence of the G2019S mutation among Moroccan PD patients and to situate these findings within broader regional and international epidemiological trends. Conducted at the University Hospital Center (CHU) of Fès, the research involved 78 patients followed by the Neurology Department, all of whom met established clinical criteria for idiopathic PD. Molecular analysis was performed through PCR and bidirectional sequencing to detect the G2019S substitution in exon 41 of the LRRK2 gene. This investigation not only contributes to clarifying the genetic landscape of PD in Morocco but also underscores the importance of integrating molecular diagnostics into clinical neurology. Such efforts support the development of region-specific databases and foster precision medicine approaches tailored to North African populations.
