Association between tau H2 haplotype and age at onset in frontotemporal dementia

Background: The frontotemporal dementia (FTD) syndromes have been associated with the microtubule-associated tau protein since tau gene mutations have been demonstrated to be the cause of FTD and parkinsonism. linked to chromosome 17. In cases of FTD without tau gene mutations, however, it is unclear whether genetic variability in the tau gene is associated with the development or modulation of FTD. Objective: To determine whether genetic variability in tau and apolipoprotein E (ApoE) modulates and contributes to the development of FTD. Design and Patients: The distribution of tau gene haplotypes and the ApoE genotype were investigated in 86 patients with well-characterized FTD and 50 control subjects. Results: No difference in the distribution of the tau H1 and H2 haplotypes between FTD cases and controls was observed, whereas the ApoE epsilon 4 allele was more frequent in FTD cases. The. presence of at least 1 tau H2 allele was found to be significantly associated with an earlier age of onset in patients with FTD. The association between the H2 allele and age at onset was not related to family history, clinical presentation, or ApoE genotype. Conclusion: These findings support a role of tau protein in modulating disease phenotype by influencing the age at onset in these FTD cases.