Screening Newborn Infants for Disease

SCREENING NEWBORN INFANTS FOR DISEASE PAULJ. BENKE* There were lymph glands that might do him in. There were kidneys, nerve sheaths and corpuscles. There were tumors of the brain. There was Hodgkin's dhease, leukemia, amyotrophic lateral sclerosL·. There wasfertile red meadows of epithelial tissue to catch and coddle a cancer cell. There were diseases ofthe skin, dtieases ofthe bone, diseases ofthe lung, dûeases of the stomach, diseases ofthe heart, blood and arteries. There were dueases of the head, dueases ofthe neck, dueases ofthe chest, diseases ofthe intestines, düeases of the crotch. There even were diseases of the feet. There were billions ofconscientious body celL· oxidating away day and night like dumb animals at their complicatedJob ofkeeping him alive and healthy, and every one was a potential traitor andfoe. There were so many diseases that it took a truly diseased mind to even think about them as often as he and Hungry Joe did. [1] In this Catch 22 passage, Yossarian was only worried about diseases known in the time of World War II. There are more to worry about today. There are diseases of glycogen metabolism and diseases of the urea cycle, diseases of glycolysis and diseases of proteolysis. There are diseases of amino acids and diseases of organic acids, diseases of complex lipid synthesis and diseases ofcomplex lipid breakdown. There are diseases of mucolipids and diseases pf mucopolysaccharides, diseases of metabolite transport-in and diseases of metabolite transport-out. There are diseases ofimmunity and autoimmunity. There are hundreds ofnew infectious agents which can lodge in every cell in the body. There are so many additional diseases added since 1945 that it would take a Yossarian to want to test and screen children for them. Nevertheless, widespread screening for a few of these diseases should soon become a reality in the United States. Phenylketonuria (PKU) was not one of Garrod's first five postulated "inborn errors" of metabolism, but it became appreciated as one of the most common, with an incidence ofone in 15,000, and the prototype for treatable metabolic disease in man. Screening for phenylketonuria be- *Kennedy Scholar for Mental Retardation, Department of Pediatrics and the Mailman Center, University of Miami School of Medicine, Miami, Florida 33152. Supported by project 288 from the Health Services Administration, Department of Health, Education, and Welfare. 118 I Paul J. Benke · Screening of Newborn Infants came important because early detection, deletion of phenylalanine, and addition of tyrosine made a positive difference in the child's development and intellectual performance. The development of a reliable test for elevated blood phenylalanine levels in the newborn period in 1961 [2] led to compulsory testing in the state of Massachusetts in 1962. By 1967, 43 of 50 states had compulsory testing laws [3]. A discussion of screening of inherited metabolic disease has to consider the experience of PKU, and screening for this disease is not yet completely satisfactory. At least 10 percent of patients with PKU are either not screened or not detected by screening [4]. False negative tests occur, particularly if the test is administered in the first 3 days of life. Although the Guthrie screening test is remarkably effective, it picks up more apparently benign variants ofthe disease and transient but normal elevations of phenylalanine than it does patients with true disease. False positive test results mean that an infant and his parents are temporarily inconvenienced; a false negative result usually means that an infant will suffer permanent neurological disability, since an affected patient does better ifthe diet is started within 3 weeks after birth [5]. Yet, for a variety of reasons, 20 percent of affected patients are not followed up within 30 days [4]. Detection of an affected infant is the beginning of years of special care and dietary management. All of this requires the time and efforts of physicians, social workers, dieticians, psychologists, nurses, public health officials, and technologists. The experience with PKU suggests that testing and screening are most effectively done in regional centers, closely associated with a clinic that can quickly bring needed services to patients with positive test results. PKU testing also saves a society financial resources which may be as much as $4.00 for...