SCN1A-related epilepsy with recessive inheritance: Two further families

Background Variants in SCN1A gene, encoding the voltage-gated sodium channel Nav1.1, are associated with distinct epilepsy syndromes ranging from relatively benign genetic febrile seizures plus (GEFS+) to Dravet syndrome, a severe developmental and epileptic encephalopathy (DEE). Most pathogenic variants heterozygous changes inherited dominant or de novo inheritance many cause loss-of-function of one allele. To date, recessive has been suggested only two families affected children harboring homozygous missense while their parents were asymptomatic. The aim this report is describe additional which individuals have biallelic possibly explaining phenotype. Methods results We novel patients related parents. Both had fever-sensitive beginning first months life, followed by afebrile seizures, without cognitive impairment. Parents Next generation sequencing excluded variant other genes involved DEE. Estimation pathogenicity scores in-silico tools suggests that impact these less damaging than variants. Conclusion This study provides evidence can GEFS+. would imply hypomorphic may not necessarily at state but decrease seizure threshold when combined.