<unk>  is a rare human disease in which the absence of<unk><unk>  leads to accumulation of toxic levels of sulphite and neurological damage. Usually this leads to death within months of birth, due to the lack of active sulfite oxidase. Furthermore, a mutational block in<unk><unk>  biosynthesis causes absence of enyzme activity of xanthine dehydrogenase/oxidase and aldehyde oxidase.
Molybdenum cofactor deficiency
Chromium deficiency
Biotin deficiency
Copper deficiency
Vitamin D deficiency
Manganese deficiency 
Lead poisoning
Disorders of calcium metabolism