This evidence of biologic differences in genetic and sporadic FTLD suggest alterations in CSF biomarker profiles are also a possibility, although one study found similar levels of CSF tau and Aβ1−42 in genetically-confirmed FTDP-17 (n = 9) compared to sporadic FTLD (n = 17) (Rosso et al., 2003). The gene discussed is MAPT; the disease is semantic dementia.