Hypomagnesemia with secondary hypocalcemia

Hypomagnesemia with secondary hypocalcemia is an inherited condition caused by the body's inability to absorb and retain magnesium that is taken in through the diet. As a result, magnesium levels in the blood are severely low (hypomagnesemia).

Hypomagnesemia impairs the function of the parathyroid glands, which are small hormone-producing glands located in the neck. Normally, the parathyroid glands release a hormone that increases blood calcium levels when they are low. Magnesium is required for the production and release of parathyroid hormone, so when magnesium is too low, insufficient parathyroid hormone is produced and blood calcium levels are also reduced (hypocalcemia). The hypocalcemia is described as "secondary" because it occurs as a consequence of hypomagnesemia.

Shortages of magnesium and calcium can cause neurological problems that begin in infancy, including painful muscle spasms (tetany) and seizures. If left untreated, hypomagnesemia with secondary hypocalcemia can lead to developmental delay, intellectual disability, a failure to gain weight and grow at the expected rate (failure to thrive), and heart failure.