Treatment Difficulties in Hypomagnesemia Secondary to the Transient Receptor Potential Melastatin 6 Gene: A Case Report with Novel Mutation
Hüsniye Yücel1, Çiğdem Genç Sel2, Çiğdem Seher Kasapkara3, Gülin Karacan Küçükali4, Senay Savas-Erdeve4, Ülkühan Öztoprak2, Serdar Ceylaner5, Saliha Şenel1, Meltem Akçaboy11Dr. Sami Ulus Maternity and Children’s Health and Diseases Training and Research Hospital, Clinic of Pediatrics, Ankara, Turkey2Dr. Sami Ulus Maternity and Children’s Health and Diseases Training and Research Hospital, Clinic of Pediatric Neurology, Ankara, Turkey
3Dr. Sami Ulus Maternity and Children’s Health and Diseases Training and Research Hospital, Clinic of Pediatric Metabolism, Ankara, Turkey
4Sami Ulus Maternity and Children’s Health and Diseases Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey
5Intergen Genetic Center, Ankara, Turkey
Hypomagnesemia is a rare cause of seizures in childhood but should be kept in mind in recurrent and intractable seizures and hypocalcemia in communities where consanguineous marriages are common. Familial hypomagnesemia with secondary hypocalcemia is a rare genetic cause of hypomagnesemia, due to variants in the transient receptor potential melastatin 6 (TRPM6) genes. Here, a three year-old boy with a novel variant in this gene and had difficulties with enteral hypomagnesemia treatment is presented. He had recurrent seizures since two years of age and was diagnosed with epilepsy and treated with multiple antiepileptic drugs. Subsequently, he was diagnosed with rickets due to severe hypocalcemia at another center. The patient was hypotonic and neurodevelopmentally poor. The most prominent laboratory finding was of hypomagnesemia with secondary hypocalcemia. The genetic analysis revealed a novel variant in the TRPM6 gene. After parental treatment of intravenous magnesium (Mg2+) sulfate and calcium, the treatment was switched to enteral Mg2+ medications, due to persistent hypomagnesemia and the gastrointestinal side-effects, different oral preparations were used. The patient was stable on an oral maintenance dose of Mg2+ oxide with borderline blood Mg2+ levels and resolution of hypocalcemia. Hypomagnesemia is one of the causes of hypocalcemia. Enteral replacement is the key treatment but the treatment should be individualized for each patient. Normalization of hypomagnesemia is not always easy and should not be the aim of the treatment.
Keywords: Hypocalcemia, hypomagnesemia, TRPM6, transient receptor potential melastatin 6Manuscript Language: English
