Abnormal losses: medications (diuretics, laxatives, corticosteroids), gastrointestinal losses, renal losses, hypomagnesaemia, dialysisTranscellular shifts: medications: (insulin overdose, B2-sympaticomimetics, decongestants), alkalosis, thyrotoxicosis, hypothermia, head injury, myocardial ischaemiaInadequate intake: anorexia, dementia, parenteral nutrition. The gene discussed is INS; the disease is thyrotoxicosis.