CNTNAP2 and Isaacs syndrome: CASPR2-related diseases may occur comorbid with Myasthenia gravis, Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, neuromyelitis optica spectrum disorders, multiple sclerosis and myelitis.[35] Approximately 20% of patients have thymomas, most commonly those with Morvan syndrome and neuromyotonia.[45] CASPR2-related diseases are also associated with neurodevelopmental disorders such as autism, mental retardation, and epilepsy.[39,50,51] Our patient was a young man who presented with various infections, meningeal involvement and limbic encephalitis.