From past to progress: a retrospective study on CFTR genetic testing in South Africa

Confirming a genetic diagnosis of cystic fibrosis (CF) for clinically affected individuals should be more accessible today, with more laboratories offering testing and improved technologies at lower costs. Instead, diagnostic testing for CF has become more complex due to the variety of genetic testing options available for the one known causative gene (CFTR). This article provides an overview of genetic tests currently available for CF in six laboratories in South Africa. Also, it demonstrates the evolution of CF tests used at one private laboratory in the country via a ten-year retrospective study. The findings of this study may serve as a guide for healthcare providers in selecting appropriate testing for CF diagnostic or carrier genetic confirmation. The choice of genetic test and methodology depends on individualised factors such as the ethnic origin of the patient, test availability, advantages and limitations, and cost. The ethnic diversity of South Africa's populations and probable under-reporting of CF in the country make the diagnosis of this relatively common genetic condition complex. The actual burden of CF in South Africa is unknown, and comprehensive genetic testing, with an ongoing compilation of patient data in the South African CF registry, should assist in addressing the genetic diversity of CF-causing variants.