In vivo and in vitro NMR spectroscopy reveal a putative novel inborn error involving polyol metabolism

In vivo NMR spectroscopy was performed on the brain of a patient with a leukoencephalopathy, revealing unknown resonances between 3.5 and 4.0 ppm. In addition, urine and CSF of the patient were measured using high‐resolution NMR spectroscopy. Also in these in vitro spectra, unknown resonances were observed in the 3.5–4.0 ppm region. Homonuclear 1H two‐dimensional J‐resolved spectroscopy (JRES) and 1H–1H correlation spectroscopy (COSY) were performed on the patient's urine for more accurate assignment of resonances. The NMR spectroscopic studies showed that the unknown resonances could be assigned to arabinitol and ribitol. This was confirmed using gas chromatography. The arabinitol was identified as D‐arabinitol. The patient is likely to suffer from an as yet unknown inborn error of metabolism affecting D‐arabinitol and ribitol metabolism. The primary molecular defect has not been found yet. Urine spectra of patients suffering from diabetes mellitus or galactosemia were recorded for comparison. Resonances outside the 3.2–4.0 ppm region, which are the most easy to recognize in body fluid spectra, allow easy recognition of various sugars and polyols. The paper shows that NMR spectroscopy in body fluids may help identifying unknown resonances observed in in vivo NMR spectra. Copyright © 2001 John Wiley & Sons, Ltd. Abbreviations used: Cho choline‐containing compounds COSY 1H–1H correlation spectroscopy Cr creatine CSF cerebrospinal fluid GC gas chromatography Glx glutamine and glutamate JRES homonuclear 1H two‐dimensional J‐resolved spectroscopy Myo‐Ins myo‐inositol NAA N‐acetylaspartate Scyllo‐Ins scyllo‐inositol STEAM stimulated echo acquisition mode PRESS point resolved spectroscopy.