GRN and semantic dementia: The mutations of MAPT lead to abnormal intracellular accumulation of hyperphosphorylated tau.[90] While mutation of PGRN gene results in reduced expression of progranulin and is associated with Ubiquitin-TDP-43 pathology.[91] MAPT mutations typically give rise to the clinical phenotype called Frontotemporal dementia and parkinsonism linked to Chromosome 17 (FTDP-17).