Newborn Screening Technology: Proceed With Caution

Abstract
The American College of Medical Genetics (ACMG) recommends a significant expansion in the number of conditions targeted by newborn screening (NBS) programs.1 In this commentary we advocate a more cautious approach. NBS dates to the early 1960s, when the technology developed to conduct large-scale testing on dried blood spots for phenylketonuria (PKU).2 PKU remains the paradigm condition for NBS because of features of the disease and its treatment, which are particularly advantageous to population screening. It is a condition that silently causes neurologic devastation but is amenable to early detection and effective prevention with a diet of moderate burden and complexity.3 Many children affected with PKU and their families have benefited from state screening programs over the past 4 decades because of collaboration between health departments, families, primary care providers, and metabolic specialists. However, PKU screening is not an unmitigated success.4,5 There was initial uncertainty about whether children with variant forms of hyperphenylalaninemia required treatment and about whether affected children require life-long dietary management.6 Indeed, some children with benign conditions were seriously harmed from unnecessary restrictions in their diets.5 In addition, long-term studies demonstrate decrements in cognitive function for affected children and adolescents who are not fully adherent to the diet,7,8 yet adherence to the diet is challenging because of its poor palatability, high cost, and limits on insurance coverage in many policies. Affected women who are off the diet are at high risk of bearing severely neurologically impaired children.9 Only recently have many programs begun tracking affected women to enable notification, education, and management. These difficulties by no means negate the value of NBS for PKU, but they highlight the problems with the successful implementation of a population-based screening program even when a model condition is targeted. … Address correspondence to Jeffrey R. Botkin, MD, MPH, Research Administration Building, 75 South 2000 East #108, Salt Lake City, UT 84112-8930. E-mail: jeffrey.botkin{at}hsc.utah.edu