Implications of direct-to-consumer whole-exome sequencing in South Africa

Abstract

Next-generation sequencing (NGS) has truly transformed human genetics and is now an integral discovery tool in the field. Whole-exome sequencing (WES) – an NGS application focused on the proteincoding regions of the human genome – has already bridged the bench-to-bedside divide internationally and is offered as a clinical test by several accredited laboratories. Clinical WES is not currently offered in South Africa (SA) for a number of reasons, including technological constraints, insufficient storage for the resulting large datasets, ethical considerations and limitations of our understanding of the impact of human genetic variants on health and in terms of clinical utility. The historical under-representation of individuals of black African descent in genomics research further complicates the interpretation of results obtained from WES data in black Africans. Concurrently, the application of WES for preventive healthcare in seemingly healthy individuals is progressing rapidly. WES offered as a direct-to-consumer (DTC) genetic test to healthy individuals in aid of wellness and future disease risk prediction raises many critical considerations, some of which were highlighted previously in the SAMJ by the Southern African Society for Human Genetics. This topic is currently back in the headlines as local health insurance company Discovery Health launched their suite of personalised medicine products, which includes WES.[5-7] This offering is presented in partnership with US-based company Human Longevity, Inc. (HLI) under the leadership of J Craig Venter.