Outcome of the Patients Detected by Newborn Screening in Japan

A follow-up study of the cases detected by a newborn mass-screening program has been performed during 1977–1985 by a collaborative study group. The number of hyperphenylalaninemic patients detected was 148, yielding a calculated incidence of one in 82,000. Of these patients, 102 cases were confired as classical PKU, 37 cases as hyperphenylalaninemia, and 9 cases as biopterine deficiency. The ratio of biopterine deficiency to PKU was about 9%. The incidence of maple syrup urine disease was estimated as one in 580,000, and the incidence of homocystimuria and galactosemia was found to be markedly low. Our survey has accumulated 1,362 cases of histidinemia establishing an incidence of one in 9,000. We have evaluated a large-scale base to study the cad relation of histidinemia to mental development. It seems that low DQ or IQ scores of some histidinemic patients do not correspond to the blood histidine level.