Funding for this research was provided by:
Genomics Research Institute, University of Pretoria (Theme Genomica)
Text and Data Mining valid from 2018-05-22
Received: 7 April 2017
Accepted: 25 April 2018
First Online: 22 May 2018
Ethics approval and consent to participate
: Written informed consent was provided by parents or guardians for all children under the age of 18 years and assent for all children over the age of 7 years. Ethics approval to conduct the study was granted by the Research Ethics Committee of the Faculty of Health Sciences of the University of Pretoria (HREC No 315/2013). All the participants signed informed consent and assent forms for participation in the study.
: The authors declare that they have no competing interests.
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