Genetic Screening

Abstract

Advances in technology, especially DNA sequencing, have greatly increased the potential capacity of genetic screening in public health programs. In contrast to the reactive nature of most health professional activities, where professionals respond to the preexisting concerns of their patients, in screening it is the professionals who are proactive in approaching individuals who, until that point, have regarded themselves as “healthy” or “well”: the goal is to identify latent disease or future risk of disease. This is usually performed on population subgroups (often based on age, gender, and ethnicity). Screening programs include newborn, antenatal, carrier status, and disease susceptibility screening. The scope of screening has extended from the use of relatively simple and inexpensive screening tests for highly treatable conditions to a complex and diverse range of program screening for rare disorders or using complex algorithms to infer clinically relevant information, as with fetal DNA in maternal plasma.

Long-established screening criteria are being challenged by the increased capacities of laboratory systems, especially the use of high-throughput DNA sequencing. This blurs the formerly fairly clear distinction between reactive, diagnostic testing and proactive screening tests. This distinction breaks down when genome-wide methods are employed as the favored laboratory method in the diagnostic assessment of a wide range of disorders. The test being used in a diagnostic process yields up information that is incidental to the diagnostic question, so that the diagnostic test has now become also a genome-wide screening test.

This article examines the recent history of screening criteria and summarizes the ethical issues related to genetic and genomic screening.