This study examines the relationship between genetic ancestry and the rs3849942 T allele, linked to ALS, in 347 Latin American individuals from the 1000 Genomes Project. Ancestry proportions were estimated using 446 AIMs, and associations were analyzed via logistic regression. Higher Native American ancestry significantly reduced the likelihood of carrying the T allele, while European ancestry increased it. These findings emphasize the importance of incorporating genetic diversity into ALS research.