Neurons with a heterozygous mutation in the STXBP1 gene (encoding the Munc18-1 protein), which causes infantile early epileptic encephalopathy (Ohtahara syndrome), exhibited a 30% decrease in the level of Munc18-1 and 50% reduction in neurotransmitter release [109]. Here, STXBP1 is linked to early-infantile DEE.