From targeted to genome-wide DNA testing in public health screening programs—an introduction to the special issue of the European Journal of Human Genetics

More than fifty years ago, countries started to organise public health screening programs for newborns and other target groups. When phenylketonuria (PKU) turned out to be a treatable condition, and “profound cognitive impairment” could be avoided by early diagnosis followed by dietary restriction of the intake of phenylalanine, governments were very motivated to implement newborn screening (NBS) for this genetic condition [ 1 ]. Around the same time, the World Health Organization (WHO) also considered screening for tuberculosis, breast cancer, diabetes, ischemic heart disease and iron-deficiency anemia, amongst others [ 2 ]. While some consider screening as an excellent example of preventive care, others caution that screening costs money and its benefits may not always be scientifically proven. To systematically consider potential benefits and harms, the WHO developed principles of screening for disease, using newborn screening for PKU as an example [ 2 ]. These “Wilson and Jungner (W&J) principles” are used around the world to evaluate the pros and cons of potential screening programs, and to decide whether a specific screening program is worthwhile (Table 1 ). In the age of genomics, a revised version of the W&J principles was published, which paid more attention to how screening programs should be implemented [ 3 ]. Focus has been on ensuring informed choice, equity and access, quality of care and cost-effectiveness [ 3 ]. Table 1 summarizes both the traditional W&J principles and the revised version.