Cysteine is converted into pyruvate and hydrogen sulfide (H2S) through desulphuration and deamination. Then, H2S is oxidised by SQR, after which ETHE1 takes care of converting into sulfite (SO3 2-). One disorder named Ethylmalonic encephalopathy (EE) is linked to this pathway, a rare mitochondrial disease caused by variants within the ETHE1 gene. This pathway was inspired by Chapter 9 (edition 4) of the book of Blau (ISBN 3642403360 (978-3642403361)). de9 eae aka Sulfite Oxidase f4f 9783642403361 ISBN Physician's Guide to the Diagnosis, Treatment, and Follow-Up of Inherited Metabolic Diseases Springer 2014 Nenad Blau Carlo Dionisi Vici K Michael Gibson Marinus Duran ethylmalonic encephalopathy DOID:0060640 Disease ethylmalonic encephalopathy pathway PW:0002206 Pathway Ontology 20978941 PubMed Multiple sources of metabolic disturbance in ETHE1-related ethylmalonic encephalopathy. J Inherit Metab Dis 2010 Barth M Ottolenghi C Hubert L Chrétien D Serre V Gobin S Romano S Vassault A Sefiani A Ricquier D Boddaert N Brivet M de Keyzer Y Munnich A Duran M Rabier D Valayannopoulos V de Lonlay P 27856618 PubMed Coenzyme Q deficiency causes impairment of the sulfide oxidation pathway. EMBO Mol Med 2017 Ziosi M Di Meo I Kleiner G Gao XH Barca E Sanchez-Quintero MJ Tadesse S Jiang H Qiao C Rodenburg RJ Scalais E Schuelke M Willard B Hatzoglou M Tiranti V Quinzii CM