Familial primary progressive aphasia

Primary progressive aphasia (PPA) is a neurodegenerative disease presenting with isolated, progressive, language dysfunction. After at least 2 years, dementia may develop, but the aphasia predominates. Few families with hereditary PPA have been reported; some have autosomal dominance. A chromosome 17 mutation in tau exon 13 has been found in one family, and a few have linkage to chromosome 17. However, early appearance of prominent memory, behavior, and motor impairments differentiates these patients from typical PPA. The objective was to report clinical features, pathology, and genetic analysis of a family with typical PPA. We report three siblings with the typical clinical syndrome of PPA. Each presented with word-finding difficulties and early anomia. Ages at onset were 60, 61, and 65 years. Aphasia was the only symptom for at least 2 years. A nonaffected brother is 75 years of age. Family history review found no other affected relatives. Neuropathology in one patient demonstrated "dementia lacking distinctive histopathology" with ubiquitin-positive cortical neurons. DNA analysis of the proband did not detect any known mutation in tau exons 1-5, 7, or 9-13. To our knowledge, this is the first family presenting with hereditary aphasia in which typical PPA occurs in all affected members.