Genomic African and Native American Ancestry and Chagas Disease: The Bambui (Brazil) Epigen Cohort Study of Aging

PLoS Negl Trop Dis. 2016 May 16;10(5):e0004724. doi: 10.1371/journal.pntd.0004724. eCollection 2016 May.

Abstract

Background: The influence of genetic ancestry on Trypanosoma cruzi infection and Chagas disease outcomes is unknown.

Methodology/principal findings: We used 370,539 Single Nucleotide Polymorphisms (SNPs) to examine the association between individual proportions of African, European and Native American genomic ancestry with T. cruzi infection and related outcomes in 1,341 participants (aged ≥ 60 years) of the Bambui (Brazil) population-based cohort study of aging. Potential confounding variables included sociodemographic characteristics and an array of health measures. The prevalence of T. cruzi infection was 37.5% and 56.3% of those infected had a major ECG abnormality. Baseline T. cruzi infection was correlated with higher levels of African and Native American ancestry, which in turn were strongly associated with poor socioeconomic circumstances. Cardiomyopathy in infected persons was not significantly associated with African or Native American ancestry levels. Infected persons with a major ECG abnormality were at increased risk of 15-year mortality relative to their counterparts with no such abnormalities (adjusted hazard ratio = 1.80; 95% 1.41, 2.32). African and Native American ancestry levels had no significant effect modifying this association.

Conclusions/significance: Our findings indicate that African and Native American ancestry have no influence on the presence of major ECG abnormalities and had no influence on the ability of an ECG abnormality to predict mortality in older people infected with T. cruzi. In contrast, our results revealed a strong and independent association between prevalent T. cruzi infection and higher levels of African and Native American ancestry. Whether this association is a consequence of genetic background or differential exposure to infection remains to be determined.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • African Continental Ancestry Group / genetics*
  • Aging / genetics*
  • Brazil / epidemiology
  • Brazil / ethnology
  • Chagas Cardiomyopathy / epidemiology
  • Chagas Disease / epidemiology
  • Chagas Disease / ethnology*
  • Chagas Disease / genetics*
  • Chagas Disease / mortality
  • Cohort Studies
  • Electrocardiography
  • Genetic Predisposition to Disease*
  • Genomics
  • Humans
  • Indians, North American / genetics*
  • Polymorphism, Single Nucleotide
  • Prevalence
  • Proportional Hazards Models
  • Social Class
  • Trypanosoma cruzi / isolation & purification

Grant support

This work was supported by the Department of Science and Technology (DECIT, Ministry of Health) and National Fund for Scientific and Technological Development (FNDCT, Ministry of Science and Technology), Funding of Studies and Projects (FINEP, Ministry of Science and Technology, Brazil), and the Brazilian National Research Council (CNPq). MFLC, SVP, ACP, ETS and ALPR are supported by the Brazilian National Research Council (CNPq). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.