Self-limited Familial Neonatal Epilepsy due to the c.1589G > A Novel Pathogenic Variant in KCNQ2 : A Family Report

Self-limited familial neonatal epilepsy is an autosomal dominant epileptic syndrome characterized by episodes of seizures occurring in the first days of life. Most patients have heterozygous mutations of KCNQ2 gene located on 20q13. A variety of clinical phenotypes have been associated with KCNQ2 mutations, making the prediction of this rare entity difficult. Herein, we report a rare KCNQ2 variant in two siblings with self-limited familial neonatal epilepsy. The siblings had tonic seizures accompanied by clonic jerks in the first few days after birth. Genetic analysis of the siblings revealed a heterozygous KCNQ2 variant: c.1589G > A; (p.Ser530Asn). The identical variant subsequently was identified in the mother. To our knowledge, this variant has not been previously reported in individuals with KCNQ2 -related disease. This is the first report that reveals c.1589G > A variant of KCNQ2 gene as a pathogenic variant in two siblings.