A genetic epileptic syndrome characterized by the occurrence of afebrile repeated seizures in healthy infants, between the third and eighth month of life with clusters (8-10 a day) of repeated and brief episodes (2-5 minutes) over a few days. They are usually focal but can sometimes become generalized. A family history of the same epilepsy is a constant finding. The disease is genetically heterogeneous, in the majority of cases, mutations in the proline-rich transmembrane protein 2 (PRRT2) gene located at 16p11.2 have been found. Mutations have also been found in the SCN2A gene (2q24.3) encoding the brain sodium channel NaV1.2 and rarely in the KCNQ2 (20q13.33) and KCNQ3 (8q24) genes both encoding potassium channels. Additionally, three other chromosomal loci have been identified that are mapped to chromosome 19q, 16p and 1p. Transmitted as an autosomal dominant trait with incomplete penetrance. [from
SNOMEDCT_US]