Developmental changes in KCNQ2 and KCNQ3 expression in human brain: Possible contribution to the age-dependent etiology of benign familial neonatal convulsions

A Kv7.2 mutation associated with early onset epileptic encephalopathy with suppression‐burst enhances Kv7/M channel activity

“…One may speculate that no matter the impact on Kv7 channel activity, what is important is that these alterations change the dynamics of early patterns of activity that are required for proper brain development. Such patterns of activity have been described in both human premature brain (the delta brush) at stages where Kv7.2 channels are expressed, 12,13 and in rodent brain (spindle burst and early gamma oscillations) during the first postnatal week of life. [12][13][14] It has been proposed that these patterns play an important role in the formation of cortical circuits before the onset of any external sensory input.…”

“…Such patterns of activity have been described in both human premature brain (the delta brush) at stages where Kv7.2 channels are expressed, 12,13 and in rodent brain (spindle burst and early gamma oscillations) during the first postnatal week of life. [12][13][14] It has been proposed that these patterns play an important role in the formation of cortical circuits before the onset of any external sensory input. 13 Of interest, this developmental stage corresponds in rodent to a critical period, where a dominant negative mutation in KCNQ2 led to an increase in the rate of spindle burst and later to epilepsy and pathologic behavior.…”

Neonatal Seizures do not Exclude Dravet Syndrome Diagnosis

“…One possible explanation might be connected with the human neuronal inhibitory system developmental aspects. As Kanaumi et al (2008) report, KCNQ channels constitute a predominantly inhibitory system in the youngest neonates, whereas GABA-ergic transmission takes over the main inhibitory function later on [10]. However, GABAA receptors activation causes membrane depolarization in the first postnatal weeks, rather than hyperpolarization typical for mature GABA-ergic synapses.…”

Benign familial neonatal convulsions caused by mutation in KCNQ3, exon 6: A European case

“…It has been postulated that BFNC is caused by a decreased potassium current impairing repolarization of the neuronal cell membrane, which results in hyperexcitability of the central nervous system. 10 The change of p.R330C is located within the linker of pore region and S6 of KCNQ3 potassium channel. R330 is a conserved amino acid among KCNQ family, therefore it probably changes M-current by altering structure near the pore region 6.…”