Known causes of hypomagnesaemia include: Reduced dietary intake, poor gastrointestinal absorption, increased losses from the gastrointestinal tract (as in diarrhoea, vomiting and laxative use), increased renal losses (as in congenital/acquired renal tubular defects, diabetes mellitus and alcoholism) and drugs (diuretics, angiotensin converting enzyme (ACE) inhibitors, aminoglycosides, amphotericin, cyclosporine, cisplatin) [1, 6]. The gene discussed is ACE; the disease is diabetes mellitus.