Of the available plasma biomarkers, p-tau217 has shown to be the most accurate blood-based biomarker of both tau and Aβ pathologic brain changes in DS [87,88], whereas neurofilament light chain (NfL) has been found to be a sensitive, but not specific biomarker of neurodegeneration [88,89,90]. The gene discussed is NEFL; the disease is Dravet syndrome.