Can Genetic Predisposition Play a Role in Anti-Glutamic Acid Decarboxylase (GAD) Autoimmunity? A Rare Presentation in Three Siblings

Anti-glutamic acid decarboxylase (anti-GAD) autoimmunity possess a poorly understood diversity in the development of neurological manifestations with or without diabetes mellitus (DM) association. A possible genetic contribution might further expand the complexity of anti-GAD pathogenesis and demand further exploration and research. We report three siblings in the same family (two sisters and one brother) who were tested positive for anti-GAD antibodies (anti-GAD-Abs) and presented with different clinical disorders, associated with DM in one of them. Although scarce data are available in the literature concerning the influence of possible genetic predisposition on the development of anti-GAD autoimmunity, yet there is cumulative evidence to support this association which is further elucidated in this report. Whether to recommend family screening tests for patients with positive anti-GAD autoimmunity is still undetermined and further studies are required to solve the unanswered queries pertinent to this potentially treatable autoimmune disorder.