Résumé
Primary hypomagnesemia with secondary hypocalcemia(HSH) is a rare cause of hypoparathyroidism. This article presents a case of a 26-year-old male with recurrent generalized weakness and tetany, and a literature review of diagnosis and treatment of primary HSH. The biochemical tests revealed the patient had severe hypomagnesemia, mild hypocalcemia, hypokalemia, and hypoparathyroidism. Transient receptor potential melastatin-6(TRPM6) gene mutation were detected by gene test, which confirmed the diagnosis of primary HSH. The patient had been treated with long term oral magnesium supplementation, who remained asymptomatic during the follow-up. Primary HSH is a rare autosomal-recessive disorder caused by mutations in the TRPM6 gene which encoding a magnesium permeable channel expressed in the intestine and the kidney. The primary defect is impaired intestinal absorption of magnesium with secondary renal excretion, leading to a series of clinical symptoms. The treatment is mainly through lifelong magnesium supplementation.
Résumé
Primary hypomagnesemia is a rare inherited disorder and it is considered to be due to either a defect in the intestinal transport of magnesium or a defect in renal tubular transport. It is important to measure the urinary excretion of magnesium to differentiate the causes of magnesium deficiency. We report here an one-month-old female infant of primary hypomagnesemia who presented generalized tonic-clonic seizures. She had hypomagnesemia(<1.5mg/dL) and several seizure attacks but normal magnesium creatinine ratio in random urine and normal magnesium excretion in 24-hour urine. Continuous oral magnesium supplementation was necessary to avoid the recurrence of symptoms and maintain serum rnagnesium levels.