Pneumologie 2016; 70 - P401
DOI: 10.1055/s-0036-1572295

Genetic and Phenotypic Differentiation of an Andean Intermediate Altitude Population

C Eichstaedt 1, T Antao 2, A Cardona 3, L Pagani 4, T Kivisild 3, M Mormina 5
  • 1Centre for Pulmonary Hypertension at the Thoraxclinic Heidelberg, Institute of Human Genetics, University Hospital Heidelberg; Division of Biological Anthropology, University of Cambridge
  • 2Department of Vector Biology, Liverpool School of Tropical Medicine
  • 3Division of Biological Anthropology, University of Cambridge
  • 4Division of Biological Anthropology, University of Cambridge; Wellcome Trust Sanger Institute, Hinxton
  • 5Division of Biological Anthropology, University of Cambridge; Faculty of Humanities and Social Sciences, University of Winchester; School of Chemistry, University of East Anglia, Norwich

Background: Highland populations living permanently under hypobaric hypoxia have been subject of extensive research because of the relevance of their physiological adaptations for the understanding of human health and disease. In this context, what is considered high altitude is a matter of interpretation and whilst the adaptive processes at high altitude (above 3000 m) are well documented, the effects of moderate altitude (below 3000 m) on the phenotype are less well established.

Methods: In this study we assessed physiological and anthropometric characteristics as well as genetic variations in two Andean populations: the Calchaquíes (2300 m) and neighboring Collas (3500 m). We compared their phenotype and genotype to the sea-level Wichí population. We measured physiological (heart rate, oxygen saturation, respiration rate and lung function) as well as anthropometric traits (height, sitting height, weight, forearm and tibia length; n = 179). We conducted genome-wide genotyping on a subset of the sample (n = 74) and performed various scans for positive selection.

Results: At the phenotypic level, increased lung capacity was indistinguishable between both Andean groups, regardless of their living altitude and different levels of constant hypoxia. Contrarily, growth reduction in distal limbs was only observed in the high altitude population. At the genomic level, Calchaquíes revealed strong signals around the Protein Kinase, cGMP-Dependent, Type I (PRKG1) gene, suggesting that the nitric oxide pathway may be a target of selection.

Conclusion: Overall, our study shows that some phenotypic and genetic differentiation also occurs at intermediate altitude in response to moderate lifelong selection pressures.