Uncertainty also arises in novel ways in expanded newborn screening. It is well-recognized that the expansion of newborn screening has resulted in identification of some disorders for which little or no effective treatment is available, and in other instances, early identification of disorders for which the timing and severity of manifestation are uncertain — both of which give rise to concerns about labeling and stigmatization.12 Newborn screening for Krabbe disease appears to combine these two concerns, as it detects both a treatable, early-onset version of the disorder, which fits the paradigmatic phenylketonuria model for newborn screening, and also a late-onset form, which is not treatable and thus fits the Huntington’s Disease paradigm for strongly discouraging early diagnosis [D-6, Dees]. Newborn screening for common complex disorders raises similar challenges with respect to uncertainty, because of the multiple genetic contributions each common complex disorder represents. Type 1 diabetes is such a disorder, one which is currently not preventable but which presents considerable uncertainty with respect to its likelihood and severity when identified via expanded newborn screening [D-6, Kerruish].
