An interesting case of primary hypoparathyroidism

Primary hypoparathyroidism can occur due to an activating mutation of calcium sensing receptor (CaSR). Most patients remain asymptomatic and therefore not diagnosed until adulthood. We present a 38-year-old lady who had a history of muscle cramps since 8 years. She presented with vomiting, abdomen pain and body ache, showed clinical evidence of hypovolemia, severe hypocalcemia, hypokalemia, hypomagnesemia, hyperphosphatemia and metabolic alkalosis. Her 24 h urinary phosphorus was low and 24 h urinary excretion of sodium, potassium and chloride were high. Her intact parathormone was on the lower side of the normal range. She improved once we had corrected her biochemical abnormalities. By excluding acquired causes of hypoparathyroidism, we are able to conclude that this may be a case of primary hypoparathyroidism due to activating mutation of CaSR.