The KCNQ2 missense variant plays an important role in EOEE pathogenesis, and patients with KCNQ2-EOEEs mainly present with intractable seizures and IDDs.
We confirmed a genetic diagnosis in five patients (36%): epileptic encephalopathy associated with autosomal dominant de novo variants in SCN2A (p.Met1545Val), KCNQ2 (p.Asp212Tyr), and GNAO1 (p.Gly40Arg); lipoic acid synthetase deficiency due to compound heterozygous variants in LIAS (p.Ala253Pro and p.His236Gln); and encephalopathy associated with an X-linked variant in CUL4B (p.Asn211Ser).ConclusionWES is helpful at arriving genetic diagnoses in neonatal encephalopathy and/or seizures and brain damage.
Attenuating M-current suppression in vivo by a mutant Kcnq2 gene knock-in reduces seizure burden and prevents status epilepticus-induced neuronal death and epileptogenesis.
Variable expressivity of a likely pathogenic variant in KCNQ2 in a three-generation pedigree presenting with intellectual disability with childhood onset seizures.
We therefore evaluated the effects of RTG on seizures in two strains of knock-in mice harboring different Kcnq2 mutations, in comparison to the effects of phenobarbital (PB), which is the first-line antiepileptic drug for seizures in neonates.
Seizures persisting after age 6 months were reported in 31% of individuals with KCNQ2 mutations; later seizures were associated with frequent neonatal seizures.
Novel KCNQ2 and KCNQ3 mutations in a large cohort of families with benign neonatal epilepsy: first evidence for an altered channel regulation by syntaxin-1A.
Here, we set out to determine the disease mechanism of 7 de novo missense KCNQ2 mutations that were recently described in patients with a severe epileptic encephalopathy including pharmacoresistant seizures and pronounced intellectual disability.
Novel KCNQ2 and KCNQ3 mutations in a large cohort of families with benign neonatal epilepsy: first evidence for an altered channel regulation by syntaxin-1A.
In addition to benign familial neonatal epilepsy (BFNE), KCNQ2 mutations have been recently found in families with one or more family members with a severe outcome, including drug-resistant seizures with psychomotor retardation, electroencephalogram (EEG) suppression-burst pattern (Ohtahara syndrome), and distinct neuroradiological features, a condition that was named "KCNQ2 encephalopathy."
The different KCNQ2 abnormalities led to different phenotypes and included a novel intragenic duplication, c.419_430dup, in an infant with BFNS, a 0.761Mb 20q13.3 contiguous gene deletion in an infant with seizures at 3 months, and a recurrent de novo missense mutation c.881C>T in a neonate with "KCNQ2-encephalopathy."
Based on seizure frequency at onset and cognitive outcome, we delineated 3 clinical subgroups, expanding the spectrum of KCNQ2 encephalopathy to patients with moderate intellectual disability and/or infrequent seizures at onset.