Clinical and genetic ancestry profile of a large multi-centre sickle cell disease cohort in Brazil

Br J Haematol. 2018 Sep;182(6):895-908. doi: 10.1111/bjh.15462. Epub 2018 Jul 19.

Abstract

Approximately 3500 children with sickle cell disease (SCD) are born in Brazil each year, but the burden of SCD morbidity is not fully characterised. A large, multi-centre cohort was established to characterise clinical outcomes in the Brazilian SCD population and create the infrastructure to perform genotype-phenotype association studies. Eligible patients were randomly selected from participating sites and recruited at routine visits. A biorepository of blood samples was created and comprehensive demographic and clinical outcome data were entered in a centralized electronic database. Peripheral blood genome-wide single nucleotide polymorphism (SNP) genotyping was performed using a customized Transfusion Medicine (TM) Array. A total of 2795 participants at six Brazilian sites were enrolled between 2013 and 2015. The cohort included slight predominance of children <18 years (55·9%) and females (53·0%). Haemoglobin (Hb) SS was the most common SCD genotype (70·7%), followed by HbSC (23%), Sβ0 (3·0%) and Sβ+ (2·9%). SNP data from the TM Array were analysed to evaluate the genetic ancestry of the cohort and revealed significant admixture among the population. Demographics and clinical complications, stratified by age and SCD genotype, are summarized and future studies in this cohort are discussed.

Keywords: clinical aspects; sickle cell disease; single nucleotide polymorphisms.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Anemia, Sickle Cell / blood
  • Anemia, Sickle Cell / epidemiology*
  • Anemia, Sickle Cell / genetics
  • Brazil
  • Child
  • Child, Preschool
  • Cohort Studies
  • Genetic Association Studies
  • Genome-Wide Association Study
  • Genotype*
  • Hemoglobin, Sickle / analysis
  • Humans
  • Male
  • Pedigree*
  • Polymorphism, Single Nucleotide

Substances

  • Hemoglobin, Sickle