Decreased levels of dendritic spine marker proteins such as synaptosomal associated protein 27 [174] and F-actin bundling proteins (such as drebrin and moesin) [161,175,176] in DS patients also suggest synaptic defects consistent with the memory deficits seen in patients, and with abnormalities in synaptic plasticity such as LTP seen in DS-Tg model mice [177,178]. The gene discussed is MSN; the disease is Dravet syndrome.