ITPR1 autoimmunity: Frequency, neurologic phenotype, and cancer association

Autoantibodies specific for the neuronal (type 1) isoform of the ubiquitously expressed inositol trisphosphate receptor (ITPR) have been reported in 8 patients to date, 5 with cerebellar ataxia (1 with breast cancer) and 3 with peripheral neuropathy (1 with lung carcinoma and 1 with multiple myeloma).1–4 We report in this study the frequency, neurologic presentations, and oncologic associations of 14 ITPR1-immunoglobulin G (IgG)-positive patients. Acknowledgment: The authors thank John Schmeling for technical support and Mary Curtis for secretarial assistance.