We sequenced exons 1, 2 and 9–13 of MAPT in 59 Finnish patients with FTLD and analysed the MAPT haplotypes in these patients, 122 patients with early onset Alzheimer's disease (eoAD, age at onset before 65 years) and 198 healthy middle-aged controls. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.