Argentine population genetic structure: large variance in Amerindian contribution

Area of Science:

• Population Genetics
• Human Ancestry
• Genetic Epidemiology

Background:

• The genetic makeup of the Argentine population is a complex mosaic of European, Amerindian, and African ancestries.
• Previous studies have indicated a predominantly European contribution, with varying degrees of indigenous and African admixture.

Purpose of the Study:

• To precisely quantify the contributions of European, Amerindian, and African ancestries in the Argentine population.
• To identify informative genetic markers for controlling population stratification in genetic analyses.
• To evaluate the suitability of the Argentine population for admixture mapping studies.

Main Methods:

• Analysis of 78 ancestry informative markers (AIMs) in 94 individuals.
• Application of the Bayesian clustering algorithm STRUCTURE.
• Utilisation of the weighted least mean square method for comparative analysis.

Main Results:

• Mean European ancestry estimated at 78-80.2%, Amerindian at 18.1-19.4%, and African at 1.7-2.5%.
• Low levels of African admixture observed (4/94 individuals >10%).
• Significant individual variation in Amerindian (1.5-84.5%) and European admixture.

Conclusions:

• Admixture proportions in the Argentine population necessitate consideration in clinical epidemiology and genetic association studies.
• The identified informative single nucleotide polymorphisms (SNPs) can aid in controlling for population stratification.
• The substantial inter-individual admixture variance makes this population suitable for future admixture mapping studies.