Mutations in C9orf72-SMCR8 complex subunit (C9Orf72), MAPT, TREM2 and granulin precursor (GRN) have been associated with familial variants of the disease160–163, but sporadic FTD accounts for > 60% of FTD cases164. The gene discussed is C9orf72; the disease is frontotemporal dementia.