Possible association of the tau H1/H1 genotype with primary progressive aphasia.

The authors screened for tau gene mutations and polymorphisms to determine whether genetic variation at or near the tau locus contributes to the development of primary progressive aphasia (PPA). No mutations were detected in 25 patients with PPA. However, a significant overrepresentation of the tau H1/H1 genotype, also found in progressive supranuclear palsy and corticobasal degeneration, was found in the PPA group. Whether tau haplotypes have a primary causal role or whether they affect the topology of neurodegeneration remains to be determined.