Corticobasal syndrome associated with a novel 1048_1049insG progranulin mutation

Mutations in the progranulin gene ( GRN ) cause familial frontotemporal lobar degeneration (FTLD) associated with type 3 TDP-43 positive inclusions.1 The clinical phenotype associated with progranulin mutations continues to be defined, although patients present usually with either behavioural symptoms (behavioural variant FTLD) or a progressive aphasia. However, patients have also been described with a corticobasal syndrome (CBS), extending the pathological associations of this disorder into the TDP-43 proteinopathies.1 Neuroanatomically, CBS is usually associated with asymmetrical frontal and parietal lobe deficits, and there is evidence that progranulin mutations are also associated with early parietal lobe involvement and asymmetrical hemispheric atrophy.2 We describe a novel mutation in the GRN gene causing a CBS in family DRC219. This family was originally described as having “familial dementia lacking specific pathological features presenting with clinical features of corticobasal degeneration” in Brown et al .3 DRC219 is a family from the south of England with a history of an autosomal dominant dementia. The proband was seen and investigated at the National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. Her grandmother died aged 61 and had been said to have abnormal behaviour for a few years prior to death. Her mother died aged 54, with the onset of memory and behavioural problems in her 40s, as well as a left hemiparesis. The proband’s brother also had a progressive behavioural syndrome with symptoms of inappropriate social behaviour …