Long-term follow-up of a patient with primary hypomagnesaemia and secondary hypocalcaemia due to a novel TRPM6 mutation

Abstract

Hypomagnesaemia with secondary hypocalcaemia (HSH) is a rare condition usually presenting in the newborn period as refractory seizures, other symptoms of increased neuromuscular excitability and growth disturbances. A case with a novel TRPM6 mutation with an excellent long-term outcome is reported to highlight the observation that clinical suspicion is essential for an early diagnosis and treatment of HSH. The compliance of a long-term treatment with oral magnesium supplements is critical to avoid abnormalities of neurological and physical development. The finding of novel mutations supports the notion that the molecular study of the whole TRPM6 gene is required for diagnostic accuracy. Furthermore, the molecular study of the different types of hereditary hypomagnesaemia is critical to further improve our knowledge of magnesium homeostasis.

A Novel Homozygous Mutation in the Transient Receptor Potential Melastatin 6 Gene: A Case Report

“…In this article, we describe the clinical phenotype and follow-up of a patient with HSH due to a novel frame-shift mutation in the TRMP6 gene. Similar to previous reports which state that the onset of the disease is in early infancy at an average age of 4.9 weeks (4-12 weeks), our patient had also presented in early infancy ( 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ). Also, similar to previously reported cases, our patient had presented with seizures, a symptom which is the most common manifestation of primary hypomagnesemia in children ( 8 , 9 , 10 , 11 , 12 ).…”

“…To the best of our knowledge, to date, fewer than 80 cases with TRPM6 gene mutation and 48 different mutations have been reported worldwide ( 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 19 ). The identified TRPM6 mutations were distributed over the whole gene, without clustering in any specific domain, consistent with the allelic heterogeneity ( 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 19 ). Genotype-phenotype correlation has not been evaluated properly.…”