How Human Genetics Came to Sa

S33 June 2016, Vol. 106, No. 6 (Suppl 1) The massive strides made in human genetics in the last 10 years would not have been possible without the diligent and insightful work of the pioneers in human genetics. This is particularly true in South Africa (SA), where a small community of scientists and clinicians have been responsible for the application of scientific/ medical advances into the wider SA population. Prof. Peter Beighton spearheaded the initial retinal degenerative disorder (RDD) research project in 1985, the emphasis being the identification of genes underlying RDD in SA families. The RDD genes affect the rod and cone photoreceptors of the retina, resulting in retinal degeneration and consequent loss of vision, which may result in total blindness. At the time the project was initiated, it was believed there were, at most, three genes responsible for the most common RDD, namely retinitis pigmentosa (RP): one each for the autosomal dominant (ADRP), the autosomal recessive (ARRP) and the X-linked inherited (XLRP) forms. To date, however, there are 21, 34 and 2 genes for these forms of RP, respectively,[1] and over 230 genes for all forms of RDD worldwide. Generally, inherited RDDs are a challenging group of disorders to characterise, as they display vast clinical and genetic heterogeneity. Nevertheless, providing a genetic diagnosis to patients affords several benefits, including predictive, carrier and diagnostic testing for family members and participation in current and future gene-based clinical trials. Genetics in SA has its own unique challenges; the populations, both local and immigrant, exhibit genetic diversity of a higher order than other population groups.[2] Some groups have remained genetically isolated from each other, while others exhibit significant admixture. These phenomena have collectively contributed to unique, local variations in gene frequencies, noted in all SA population groups, which has further confounded genetic diagnosis for RDDs. Nevertheless, ‘gene-hunting’ for this group of disorders in SA has changed dramatically over the 25 years since the project began, largely through evolving molecular technologies, together with the computational era and increasing bioinformatics capabilities. This article gives an overview of the research efforts in SA into RDD.