Genetic carrier screening has been successfully used over the last decades to identify individuals at risk of transmitting specific DNA variants to their newborns, thus having an affected child. Traditional testing has been offered based on familial and/or ethnic backgrounds. The development of high-throughput technologies, such as next-generations sequencing, able to allow the study of large genomic regions in a time and cost-affordable way, has moved carrier screening toward a more comprehensive and extensive approach, i.e., expanded carrier screening (ECS). ECS simultaneously analyses several disease-related genes and better estimates individuals' carrier status. Indeed, it is not influenced by ethnicity and is not limited to a subset of mutations that may arise from poor information in some populations. Moreover, if couples carry out ECS before conceiving a baby, it allows them to obtain a complete estimation of their genetic risk and the possibility to make an informed decision regarding their reproductive life. Despite these advantages, some weakness still exists regarding, for example, the number of genes and the kind of diseases to be analyzed and the interpretation and communication of the obtained results. Once these points are fixed, it is expectable that ECS will become an ever more frequent practice in clinical settings.
Keywords: expanded carrier screening; genetic carrier screening; genetic counselling; next generation sequencing; recessive genetic disease.