We then examined the regulation of one‐carbon‐related amino acids in the brain of a mouse model of Dravet syndrome (Scn1A+/−), a CBD responsive condition in humans (Thiele et al., 2018), and identified altered levels of glycine, methionine, and cysteine, implicating dysregulation of one‐carbon metabolism in this disease. Here, SCN1A is linked to encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.