CNTNAP1 and immune system disorder: In conclusion, our data reveal the novel finding that the auto‐immune response against CASPR1, a known antigen in auto‐immune disease (Querol & Illa, 2015; Stathopoulos et al, 2015), not only targets the paranodal region of myelinated nerves, but also targets retinal synapses both at a structural and functional level at a very early time point.