Novel mutations in TRPM6 gene associated with primary hypomagnesemia with secondary hypocalcemia. Case report

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2021 Nov;165(4):454-457. doi: 10.5507/bp.2021.027. Epub 2021 May 18.

Abstract

Background: Primary hypomagnesemia with secondary hypocalcemia (HSH) is a rare genetic disorder. Dysfunctional transient receptor potential melastatin 6 causes impaired intestinal absorption of magnesium, leading to low serum levels accompanied by hypocalcemia. Typical signs at initial manifestation are generalized seizures, tetany, and/or muscle spasms.

Case report: We present a 5 w/o female manifesting tonic-clonic seizures. Laboratory tests detected severe hypomagnesemia and hypocalcemia. The molecular genetic analysis revealed two novel mutations within the TRPM6 gene c.3308dupC (p.Pro1104Thrfs*28) (p.P1104Tfs*28) and c.3958C>T (p.Gln1302*) (p.Q1302*) and the patient was successfully treated with Mg supplementation.

Conclusion: Ion disbalance should be taken into account in the differential diagnosis of infantile seizures. Accurate diagnosis of HSH together with appropriate treatment are crucial to prevent irreversible neurological outcomes.

Keywords: hypocalcemia; hypomagnesemia; infantile seizures; transient receptor potential melastatin 6.

Publication types

  • Case Reports

MeSH terms

  • Female
  • Humans
  • Hypercalciuria
  • Hypocalcemia* / genetics
  • Magnesium
  • Magnesium Deficiency* / congenital
  • Magnesium Deficiency* / genetics
  • Mutation
  • Nephrocalcinosis
  • Renal Tubular Transport, Inborn Errors
  • Seizures / genetics
  • TRPM Cation Channels* / genetics

Substances

  • TRPM Cation Channels
  • TRPM6 protein, human
  • Magnesium

Supplementary concepts

  • Hypomagnesemia 1, Intestinal
  • Hypomagnesemia primary