Two years of PKU testing in California. The role of the laboratory.

A cooperative phenylketonuria screening program involving private nongovernmental laboratories, individual physicians and local and state health departments has been in operation for two years. The system has evolved to the point where practically all newborns are tested. The accuracy of laboratory work has been verified by an ongoing evaluation program which has resulted in continual improvement in level of performance. There are two areas in which some beneficial changes might be considered. One is the reduction of costs of the testing and follow-up by increasing volume and centralization of work. The other is greater cooperation of the medical community in collecting the data necessary to evaluate the program and expedite the final diagnosis.