Thyroid crisis associated with severe hypocalcemia.

A 30-year-old woman with thyroid crisis and impaired renal function presented with severe hypocalcemia. She had already had hypocalcemia one yr previously when her serum creatinine level was normal. A normal level of serum amino terminal fragment of parathyroid hormone in spite of severe hypocalcemia suggested impairment of parathyroid function. Since her serum magnesium was normal and she had no history of neck surgery or radioiodine therapy, her hypoparathyroidism was considered to be idiopathic. This is the seventh case with co-existing Graves' disease and idiopathic hypoparathyroidism reported in the literature.