TITLE:
Hypomagnesemia with Secondary Hypocalcemia Linked to a Novel TRPM6 Gene Mutation
AUTHORS:
Amel Tej, Bernd Dworniczak, Asma Marzouk, Najla Soyah, Samia Tilouche, Moez Gribaa, Jihène Bouguila, Lamia Boughamoura
KEYWORDS:
Magnesium, Hypomagnesemia, Hypocalcemia, Convulsion, TRPM6
JOURNAL NAME:
Open Journal of Pediatrics,
Vol.6 No.4,
November
21,
2016
ABSTRACT: Hypomagnesemia
with secondary hypocalcemia (HSH) is a rare inherited disorder, characterized
by extremely low levels of serum magesium associated with symptomatic hypocalcemia.
HSH manifests in the new born period with neurological symptoms, including
generalized seizures, which are refractory to anticonvulsant treatment. In this
disorder, the basic abnormality is the defective intestinal absorption of
magnesium. Mutations in TRPM6, the gene encoding the transient receptor
potential cation channel subfamily member 6 have been found to be responsible
for this disease. We report on a four-month-old Tunisian girl who presented
with convulsions. Laboratory evaluation yielded extremely low serum magnesium
levels, low calcium levels, and abnormal PTH levels. The diagnosis of HSH was
confirmed by mutation analysis which identified the novel mutation c.1307A >G in exon 11 of TRPM6
(Lys436Arg). Our patient was homozygous for this mutation. Prenatal diagnosis was done during second pregnancy. DNA from trophoblast
biopsy showed the same mutation as the proband.