Variability and positive selection in FOXP2, a gene associated with the development of language, speech, and cognition

Introduction: the FOXP2 gene has been identified as a key genetic factor in the development of language and human cognition. Mutations in FOXP2 have been associated with language disorders and speech difficulties. Additionally, this gene has been linked to various neuropsychiatric conditions. The objective of this study is to analyze the genetic differentiation of populations in the FOXP2 gene and in the rs10447760, rs1456031, rs2253478 and rs2396753 polymorphisms. Method: data from the "1000 Genomes" Project were used to analyze genetic variability in FOXP2 in 2504 individuals from 26 populations and 5 macro populations. Linkage disequilibrium, Hardy-Weinberg equilibrium and allele frequencies of the SNPs were evaluated. Genetic differentiation was estimated using the FST statistic. Results: a highly differentiated region was identified in intron 3 of FOXP2 between the African macro population and the rest, with a maximum FST of 0,78. This region contains an epigenetic mark H3K27Ac, suggesting a regulatory role. Hardy-Weinberg imbalances were observed in some populations for the SNPs analyzed. Linkage disequilibrium analysis showed that these SNPs have independent effects. Conclusions: the highly differentiated region in FOXP2 suggests a past natural selection event, supporting an adaptive role of this gene in the evolution of language, speech and cognition. Population differences in Hardy-Weinberg equilibrium and genetic variability highlight the importance of considering genetic variation in future association studies with FOXP2