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A European survey of prenatal diagnosis cases involving urea cycle diseases was performed. Citrullinemia was the most frequently investigated disease (108 cases). Other diseases are, in order of frequency, argininosuccinic aciduria (75 cases), ornithine transcarbamylase defect (52 cases), carbamoylphosphate synthetase defect (8 cases), triple H (3 cases), and arginase deficiency (1 case). Only one disease (ornithine transcarbamylase defect) is presently diagnosed using molecular biology methods. © 1995 Wiley-Liss, Inc.

In patients with phenylketonuria (PKU; McKusick 261600) CSF concentrations of catecholamines may be reduced to levels similar to those found in Parkinson disease (Pinder et al 1976; Lou et al 1987). Dopaminergic neurotransmission within the visual system is present at the level of the retina, the lateral geniculate nucleus and the visual cortex (Phillis et al 1967; Dyer et al 1981; Gottlob et al 1989). Depending on the severity of the disease and the methods used, abnormal delay in visual evoked potential (VEP) of parkinsonian patients was found to be restored following L-DOPA therapy (Bodis-Wollner et al 1982). Prolonged latencies of VEP were also found in patients with PKU

The red pigment uroerythrin, a chromophore known to be adsorbed by the amorphous urate sediments (sedimentum lateritium), has been isolated from human urine and further purified as its trimethyl derivative. Urine was applied to a column of Amberlite XAD-2 resin on which uroerythrin and other pigments were adsorbed. The pigments were eluted with methanol and uroerythrin was further purified by extraction with ether at pH 4.0, repeated chromatography on lipophilic Sephadex LH-20 and thin-layer chromatography on silica gel. For optimal purification uroerythrin was converted into the trimethyl derivative and chromatographed on silical gel thin-layer plates. The structure of the pigment has been studied by chromate degradation followed by identification of the imide products by thin-layer chromatography. From these results and from infrared, mass spectral and nuclear magnetic resonance data a tripyrrole structure for uroerythrin is concluded. The proposed structure for the chromophore is related to that of the bile pigment biliverdin consisting, however, only of the rings A, B and C.

A protein load with an ensuing 20 hr fast was performed to assess the function of biotin dependent carboxylases in 3 girls with Rett syndrome. In plasma a moderate increase of ammonia and propionate was found. The fact that these discrete biochemical alterations were found in all of the patients supports earlier conclusions that further studies on biotin metabolism and carboxylase function should be performed, perhaps preferably in cerebrospinal fluid.

A second patient with N-acetylglutamate synthetase deficiency is described. The first symptoms were noted at 6 days of age. The course was lethal despite vigorous treatment. The diagnosis was established after death.

Les auteurs exposent un cas de deficit en 3-hydroxy-3-Methylglutaryl-CoA-Lyase survenu chez un nourrisson feminin de 1 an