Chronic calcium pyrophosphate crystal deposition disease arthropathy associated with hypomagnesemia

We describe a case of a young woman with a magnesium renal wasting syndrome leading to severe hypomagnesemia and a chronic pseudoosteoarthritis calcium pyrophosphate crystal deposition disease (CPDD) arthropathy. A chronic CPDD arthropathy secondary to hypomagnesemia has not been previously reported. The identification of CPDD, particularly in the young, can be a clue to the presence of a potentially treatable underlying metabolic disorder, such as hypomagnesemia.