Impressive efficacy of the ketogenic diet in a KCNQ2 encephalopathy infant: a case report and exhaustive literature review

• Published in: Translational pediatrics Vol. 12; no. 2; pp. 292 - 300
• Main Authors: Falsaperla, Raffaele, Marino, Simona Domenica, Salomone, Giulia, Madia, Francesca, Marino, Silvia, Tardino, Lucia Giovanna, Scalia, Bruna, Ruggieri, Martino
• Format: Journal Article
• Language: English
• Published: China AME Publishing Company 28-02-2023
• Subjects: Case Report; KCNQ2 gene; case report; Developmental and epileptic encephalopathy; ketogenic diet (KD); infant
• ISSN: 2224-4344; 2224-4336; 2224-4344
• DOI: 10.21037/tp-22-258

KCNQ2 encephalopathy is characterized by neonatal-onset epilepsy and developmental impairment, due to "de novo" KCNQ2 pathogenic variants. According to literature data, sodium channel blocking agents appear to be the best treatment options for the disease. Reports describing the use of ketogenic diet (KD) in the KCNQ2 pediatric population are limited. The non-conservative amino acid substitution p.Ser122Leu in KCNQ2 is associated with a broad spectrum of inheritance modalities, clinical phenotypes and outcomes; no previous reports of the same variant treated with KD are available in literature.
We described a 22-month-old female with seizure onset on day 2 of life. At three months of age, she presented refractory status epilepticus (SE) that did not respond to midazolam and carbamazepine, which was added once a "de novo" p.Ser122Leu KCNQ2 variant was demonstrated. KD was the only treatment that led to cessation of seizures. The baby maintained seizures remission and achieved neurodevelopmental milestones.
To define an overt genotype-phenotype correlation for KCNQ2 pathogenic variants is a challenge; we propose the KD as a valuable treatment for refractory seizures and impaired neurodevelopment in infants harboring "de novo" mutations in the KCNQ2 gene.