[Newborn mass-screening programme for histidinaemia: increased efficiency through selective thin-layer chromatography (author's transl)].

Histidinaemia, detected on urinary screening in cases which had not been discovered by neonatal blood screening induced us to lower the control limit for histidine from 6 to 4 mg/dl. This was possible by the development of a thin-layer chromatographic control method for the Guthrie test. The combination of thin-layer chromatography (TLC) and the Guthrie test (GT) proved to be considerably more efficient than the Guthrie test alone: among 44,510 newborn infants tested in the first six months of 1975 twice as many cases of histidinaemia were found (TLC + GT 6, GT 3) in spite of a gready lowered control rate (TLC + GT 0.4%, GT 2.4%). Of 87,729 newborn infants tested in 1975, 9 cases of histidinaemia were detected (incidence: 1 in 9,748). Only 4 of these infants showed initial blood levels of larger than or equal to 6 mg/dl. 5 children with histidinaemia, 3 with an initial level of 4 mg/dl and one each with 5 and 8 mg/dl, respectively, had to be put on a histidine-restricted diet becuase the blood histidine level was constantly elevated above 8 mg/dl. The further course of histidinaemia does not appear to correlated with the height of the initial blood histidine level.