[Gene mixture in a population sample from Buenos Aires City]

Area of Science:

• Population Genetics
• Human Genetics
• Forensic Anthropology

Background:

• Understanding population genetic structure is crucial for demographic and historical interpretations.
• Buenos Aires, a major South American metropolis, has a complex demographic history shaped by European, Amerindian, and African migrations.
• Previous genetic admixture studies in Buenos Aires have yielded varied results, necessitating further investigation.

Purpose of the Study:

• To estimate the gene admixture proportions of Amerindian and African ancestry in the population of Buenos Aires City.
• To analyze erythrocyte genetic systems and GM/KM allotypes in blood donors from a public health center.
• To compare admixture results with a prior study from a private healthcare institution.

Main Methods:

• Analysis of 218 unrelated blood donors from Hospital de Clínicas, Buenos Aires.
• Genotyping of eight erythrocyte genetic systems and GM/KM allotypes.
• Gene frequency calculation using maximum likelihood and admixture analysis with the ADMIX program.

Main Results:

• The estimated Amerindian genetic contribution was 15.8%, and the African contribution was 4.3%.
• Significant differences in gene admixture were observed when compared to a previous study at Hospital Italiano, except for the KM system.
• The calculated gene frequencies and admixture proportions are consistent with the known demographic and historical context of Buenos Aires.

Conclusions:

• The genetic makeup of Buenos Aires blood donors reflects a significant Amerindian and African ancestral component.
• The study highlights potential variations in genetic admixture estimates between public and private healthcare samples.
• The findings support the historical narrative of population formation in Buenos Aires City.