This is an intriguing association as both conditions have been associated with brain deposits of phosphorylated tau protein.<h4>Conclusion</h4>IgLON5 Abs may be observed in patients with a diagnosis of CJD; it is unknown whether a synergistic effect of IgLON5 Abs with CJD exists, increasing neurodegenerative changes. The gene discussed is MAPT; the disease is Creutzfeldt Jacob disease.