How this study might affect research, practice or policy– Patients positive for anti-GAD65 should be screened for anti-CN1A-associated diseases, and broader evaluation of anti-CN1A in anti-GAD65-related autoimmune conditions (e.g., type 1 diabetes, vitiligo, Hashimoto’s thyroiditis) may clarify links between systemic autoimmunity and epilepsy. This evidence concerns the gene GAD2 and Hashimoto thyroiditis.