TRPM6 Gene Mutation: A Treatable Cause of Epilepsia Partialis Continua in Infancy

A bstract This study reports the case of a 5-month-old infant who had epileptia partialis continua (EPC) for 2 days. The first episode of similar discrete attacks occurred at the age of 30 days. Her blood counts and serum chemistry were normal, except low serum magnesium, calcium, and parathyroid hormone level. Urinary magnesium and calcium were normal. She was treated with intravenous magnesium and calcium. She was switched to oral magnesium but experienced a drop in the serum magnesium level; therefore, intestinal malabsorption was considered. Clinical exome sequencing revealed a homozygous deletion in transient receptor potential melastatin 6 gene. At 11 months of age, she had mild developmental delay and is seizure-free and required a high dose of oral magnesium. It is important to consider hypomagnesemia as a cause of neonatal seizure and EPC, and attention to dose modification is needed to prevent a break through seizure and improve the neurological outcomes.