title: Neonatal variables, altitude of residence and Aymara ancestry in northern Chile.
abstract: Studies performed in the Andean plateau, one of the highest inhabited areas in the world, have reported that reduced availability of oxygen is associated to fetal growth retardation and lower birth weight, which are established predictors of morbidity and mortality during the first year of life. To test this hypothesis, perinatal variables of neonates born at the Juan Noé Hospital of Arica, Chile, were analyzed in relation to altitude of residence and Aymara ancestry of their mothers. The study population comprised the offspring of 5,295 mothers born between February 2004 and August 2010. Information included birth weight, height, head circumference, gestational age, altitude of residence and socioeconomic status, and was obtained from medical records. Mother´s ancestry was assessed based on surnames which were linked to percentages of Aymara admixture estimates relying on 40 selected ancestry informative markers. After correcting for the effect of multicollinearity among predictor variables, neonates born to mothers with an increased component of Aymara ancestry showed significantly higher birth weight and height at sea level, a marginally significant (p-value 0.06) decrease of birth weight and a significant decrease of height with altitude in comparison with the offspring of mothers with low Aymara ancestry. Since observed tendencies are suggestive of a possible genetic adaptation to hypoxia of the Chilean Aymara, we discuss briefly preliminary evidence related to fetal oxygen transport, particularly polymorphisms in the promoters of the HBG1 and HBG2 genes that are modulators of HbF synthesis, obtained in this ethnic group.
authors.affiliation: Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile; Centro de Investigaciones del Hombre en el Desierto (CIHDE), Arica, Chile.
authors.forename: Francisco
authors.initials: F
authors.lastname: Rothhammer
authors.affiliation: Departmento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile.
authors.forename: Macarena
authors.initials: M
authors.lastname: Fuentes-Guajardo
authors.affiliation: Center for Computational Genomics, Institute of Applied Genetics, University of North Texas Health Science Center, Fort Worth, Texas, United State of America.
authors.forename: Ranajit
authors.initials: R
authors.lastname: Chakraborty
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Justo
authors.initials: J
authors.lastname: Lorenzo Bermejo
authors.affiliation: Department of Human Biology, Zoological Institute, Christian Albrechts-University, Kiel, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Dittmar
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D000531:Altitude; D001724:Birth Weight / Q000502:physiology*; D049628:Body Size / Q000502:physiology*; D002677:Chile; D005260:Female; D005319:Fetal Hemoglobin / Q000378:metabolism; D005865:Gestational Age; D006257:Head / Q000502:physiology; D006801:Humans; D000860:Hypoxia; D007199:Indians, South American / Q000235:genetics; D007231:Infant, Newborn; D008297:Male; D009035:Mothers; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012044:Regression Analysis; D012189:Retrospective Studies; D012923:Social Class; D055815:Young Adult; D055545:gamma-Globins / Q000235:genetics
chemical_list: D055545:gamma-Globins; D005319:Fetal Hemoglobin