Molybdenum Cofactor Deficiency, Complementation Group B, also known as sulfite oxidase deficiency due to molybdenum cofactor deficiency type b, is related to encephalomalacia and hyperekplexia, and has symptoms including opisthotonus An important gene associated with Molybdenum Cofactor Deficiency, Complementation Group B is MOCS2 (Molybdenum Cofactor Synthesis 2), and among its related pathways/superpathways are Metabolism and Metabolism of water-soluble vitamins and cofactors. Affiliated tissues include eye and kidney, and related phenotypes are nystagmus and hypotonia