Although most genetic conditions are relatively rare, certain genetic conditions occur with such high frequency in a population that they are of concern to most everyone. Such traits may be worthy of population-based screening provided that certain basic requirements are met. There are only a few checkpoints through which virtually everyone in a society passes, one of which is the newborn nursery. In addition, the newborn period is the earliest point following birth, and therefore any damage that is done to the body as a result of the disease has had minimal time to progress.

A disease much meet certain criteria if it is to be considered a valid candidate for newborn screening. First, the disease must be relatively common in the target population. It must have a serious health consequence, and the condition must be either treatable or preventable. There would be little...