RT Journal A1 Szeinberg A, Cohen BE, Golan R, Peled I, Lavi U, Crispin M T1 PErsistent mild hyperphenylalaninemia in various ethnic groups in israel JF American Journal of Diseases of Children JO American Journal of Diseases of Children YR 1969 FD October 1 VO 118 IS 4 SP 559 OP 564 DO 10.1001/archpedi.1969.02100040561003 UL http://dx.doi.org/10.1001/archpedi.1969.02100040561003 AB CLASSICAL PHENYLKETONURIA (PKU) may be defined as a hereditary metabolic disorder due to phenylalanine hydroxylase deficiency, leading to persistently very elevated blood phenylalanine levels (above 20 mg/100 cc) and urinary excretion of phenylpyruvic acid. Recently introduced programs for mass screening of newborn for the detection of this disease revealed that hyperphenylalaninemia may represent a sign of several distinct disorders.1-4 In the present communication, we report on the occurrence of a type named "persistent mild hyperphenylalaninemia"4 in the Israeli population. The genetic nature of this type is discussed.MethodsĀ  Screening for PKU in the newborn was performed by the method of Guthrie and Susi5 usually at the age of 3 to 5 days. When a presumptive positive result was observed, additional samples of blood dried on filter paper were requested and examined by the Guthrie method as well as a paper chromatographic screening procedure for amino acids.6