Fig. Participant's responses are captured in real-time using REDCap Mobile on Tablets.
Using questionnaires and clinician evaluation, children and their families provide a wealth of medical, behavioral, and cognitive data. Assessments are delivered in the following local languages: English, Afrikaans, and Xhosa (in South Africa), and Kiswahili and Kigiryama (in Kenya). A summary of the assessment tools is found below and available for download here.
Blood samples are collected from all participants. These samples are sent to laboratories both in South Africa and in the USA for DNA extraction and analysis. Information from the DNA is then stored in the NIMH biobank (RUCDR in the USA) for analysis.
All the blood samples collected for NeuroDev will be genotyped and exome sequenced. The primary goal of our analysis is to identify rare variants in the DNA that cause developmental delay (particularly ASD, ID, and ADHD). We do this by looking first at newly occurring (“de novo”) changes in the DNA of children (i.e. these changes are not present in their parents DNA). We compare those changes to reference databases with the DNA of “control” individuals, as well as databases with lists of known disease-causing genes (for example OMIM). A secondary goal is to identify common variations in DNA that can be inherited from parents and are known to be associated with delayed development.
If DNA analysis of a participant in South Africa and Nairobi, Kenya is conclusive for a genetic sequence known to cause developmental delay, this result will be confirmed, and the information returned to the particular participating family. The study team in Kilifi, Kenya continues to explore the ethics of returning genetic results in their context.
Genetic analysis is changing at such a fast pace that the types of analysis available for NeuroDev data are constantly expanding. If funding is available, we hope to analyze the whole genome on some individuals and create stem cells (iPSc) on a small number of those who have agreed.