Complement activation has been well‐described in other neurological conditions, including epilepsy (eg, postviral epilepsy, CASPR2‐associated encephalitis, and Rasmussen's syndrome),40, 41 major psychiatric disorders (eg, major depressive disorder and schizophrenia),42 and neurological disorders (eg, Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, and parkinsonism).43 Here, CNTNAP2 is linked to juvenile Huntington disease.