先天性代謝異常症の新生児マススクリーニングの現状と問題点

抄録

Mass screening for inborn errors of metabolism is a unique means for prevention of handicapped children. A nation-wide screening pro-gram for 5 inborn metabolic diseases, namely PKU, maple syrup urine disease, homocystinuria, histidinemia and galactosemia, started in October 1977 in Japan, and at the end of 1979 fiscal year, approximately 90% of all Japanese newborn infants were examined. Total number of newborn infants so far examined reached 3,356,388 and 547 patients were detected, including 56 PKU, 5 MSUD, 415 histidinemia and 24 galactosemia. At least one hypermethioninemic patient was biochemically proved to be homocystinuric. Among 56 patients with PKU, benign hyperphenylalaninemics and at least one patient with aberrant biopterin metabolism were found after careful follow up and examination. The incidence of PKU is roughly one in 60,000, which means 1/5 that of white population. Screening method for histidinemia has much improved by introduction of thin layer chromatography detecting urocanic acid in the dried blood specimen in addition to the usual Guthrie test. Treatment of histidinemia still remains controversial. Increasing number of screening centers have in recent years been adopting Paigen-phage test in addition to the routine Beutler test. This will improve the efficiency of galactosemia detection in the near future. A new screening program for congenital hypothyroidism just started in 1980. Provisional surveys so far carried out promise fruitful results.