For a study, the researchers sought to determine if CGG repeat expansion in LRP12, NUTM2B-AS1, and GIPC1 were present in a group of patients with movement disorders. In 1,346 movement disorder patients and 1,451 matched healthy controls, they looked for CGG repeat expansion in LRP12, NUTM2B-AS1, and GIPC1. In LRP12 and NUTM2B-AS1, no patients or controls had extended CGG repeats, whereas 16 patients had more than 40 CGG repeats in GIPC1, with 11 of these patients having more than 60 CGG repeats. Just 1 healthy control had an increased GIPC1 allele (83 CGG units), implying that GIPC1 CGG repeat expansion was present in about 1% of individuals with movement disorders in the cohort and that it was extremely rare in healthy controls (<0.001). Patients with GIPC1 CGG repeats had clinical characteristics strikingly similar to those with NOTCH2NLC GGC repeat-positive movement disorders. Furthermore, the GIPC1 CGG repeat-positive individuals had white-matter hyperintensities in the corticomedullary junction but no typical NOTCH2NLC-related high-intensity signals. Furthermore, 44% of GIPC1 CGG repeat-positive individuals had a cognitive disability, and skin biopsies demonstrated intranuclear inclusion deposits in 2 patients. The CGG repeat expansion in GIPC1 might be linked to phenotypes of movement disorders and diseases involving intranuclear inclusions.