Lee A, et al. - Researchers compared patients with amyotrophic lateral sclerosis (ALS) with controls to investigate if higher plasma levels of formaldehyde (FA) may be detected in the former group relative to the latter, and to explore changes in levels of FA precursors. From the Motor Neuron Disease clinic at the Royal Brisbane & Women's Hospital, they recruited 40 heathy controls and 50 ALS patients. By employing an FA detection assay, they quantified plasma FA levels. By means of multiple reaction monitoring mass spectrometry, they measured trimethylamine (TMA) and trimethylamine oxide (TMAO) in plasma. They noted that some patients with ALS exhibited elevated FA. A significant positive correlation was identified between levels of TMA and TMAO and plasma FA levels. FA levels displayed no link with disability measured with the ALS functional rating scale, with the duration of disease or with the age of the participants. FA was identified as neurotoxic and its contribution to disease pathogenesis was suggested.