Numerous kindreds with familial frontotemporal lobar degeneration have been 
linked to mutations in microtubule-associated protein tau (MAPT) or progranulin 
(GRN) genes. While there are many similarities in the clinical manifestations 
and associated neuroimaging findings, there are also distinct differences. In 
this review, we compare and contrast the demographic/inheritance 
characteristics, histopathology, pathophysiology, clinical aspects, and key 
neuroimaging findings between those with MAPT and GRN mutations.