Thesis title: Towards the development of retrospective molecular autopsies in unexplained sudden unexpected death cases
Supervisors: A/Prof Laura Heathfield and Yuvika Vandayar

Following a post-mortem investigation, the cause of death remains undetermined in up to 10% of sudden unexpected death (SUD) cases locally. Fortunately, with the introduction of molecular autopsy, many of these cases may be resolved. There are however several challenges in implementing a post-mortem genetic test, especially retrospectively, with one of the most prominent being the lack of a good quality DNA sample. A retrospective molecular autopsy may be valuable in alleviating the burden of historical unexplained SUD cases wherein prospective sampling is no longer possible. Consequently, archival samples to be used for DNA analyses are those that were taken during the original autopsy for ancillary investigations, i.e., femoral blood for toxicology and formalin-fixed, paraffin-embedded (FFPE) tissue for histology. These samples generally contain degraded and/or low copy number DNA. In turn, downstream molecular analyses may be hindered and the likelihood of detecting genetic variants may be reduced. It is unknown whether the genotyping assays that have been developed by Heathfield’s research group will be suitable for these archival samples stored from candidate SUD cases. To this end, DNA workflows on retrospective unexplained SUD cases will be assessed and optimised, to contribute towards the development of molecular autopsies for medico-legal investigations in South Africa. The outcome of this project will include standard operating procedures for the optimal extraction of DNA from stored biological sample(s) as well as the genotyping of at least one candidate variant that is relevant to molecular autopsies of SUD cases in South Africa