Metabolomics:Open Access

Molybdenum Cofactor and Sulfite Oxidase Deficiency

Abstract

Jochen Reiss

A universal molybdenum-containing cofactor is necessary for the activity of all eukaryotic molybdoenzymes. In humans four such enzymes are known: Sulfite oxidase, xanthine oxidoreductase, aldehyde oxidase and a mitochondrial amidoxime reducing component. Of these, sulfite oxidase is the most important and clinically relevant one. Mutations in the genes MOCS1, MOCS2 or GPHN - all encoding cofactor biosynthesis proteins - lead to molybdenum cofactor deficiency type A, B or C, respectively. All three types plus mutations in the SUOX gene responsible for isolated sulfite oxidase deficiency lead to progressive neurological disease which untreated in most cases leads to death in early childhood. Currently, only for type A of the cofactor deficiency an experimental treatment is available.