[Quantification of physiological aminoacids using aTRAQ(®) kit: evaluation and implementation of new markers].

Nowadays, physiological amino acids profiling is based primarily on ion exchange chromatography (IEC) coupled to a post-column derivatization with ninhydrin and UV detection at two wavelengths. Unfortunately, this technique suffers various drawbacks such as long analysis time, high sample volume and specific costs related to the maintenance of a dedicated equipment. These reasons have led us to consider a technology switch to a mass spectrometry method.

Quantification of hypoglycin A in serum using aTRAQ(®) assay.

Background: Hypoglycin A has been recently identified has the causal agent of atypical myopathy (AM) in horses. Its identification and quantification in equine's biological fluids is thus a major concern to confirm maple poisoning and to provide insight into the poorly understood mechanism of hypoglycin A intoxication.

Methods: Quantification of hypoglycin A has been achieved with the aTRAQ kit for amino acid analysis of physiological fluids (AB Sciex).

Diagnostic pitfall in antenatal manifestations of CPT II deficiency.

Carnitine palmitoyltransferase II (CPT2) deficiency is a rare inborn error of mitochondrial fatty acid metabolism associated with various phenotypes. Whereas most patients present with postnatal signs of energetic failure affecting muscle and liver, a small subset of patients presents antenatal malformations including brain dysgenesis and neuronal migration defects. Here, we report recurrence of severe cerebral dysgenesis with Dandy-Walker malformation in three successive pregnancies and review previously reported antenatal cases.

Surprising causes of C5-carnitine false positive results in newborn screening.

During an 18-month period, we noticed an alarming increase of newborn screening false positivity rate in identifying isovaleric acidemia. In 50 of 50 newborns presenting elevated C5-carnitine, we confirmed the presence of pivaloylcarnitine. Exogenous pivalate administration had been previously identified as the causal agent of this concern.

Evaluation of physiological amino acids profiling by tandem mass spectrometry.

Background: Nowadays, the most conventional method to quantify physiological amino acids consists in ion exchange chromatography (IEC) followed by post-column ninhydrin derivatization and UV detection at two wavelengths. Unfortunately, the technique presents some drawbacks such as long run time, large sample volume, and specific costs associated to the maintenance of a dedicated instrument. Therefore, we aimed to switch towards a mass spectrometry approach.