Characterization of the kindred of Alois Alzheimer's patient with plaque-only dementia.

We describe the kindred of Alois Alzheimer's second published patient (Johann F.) with the brain pathology typical of a subgroup of Alzheimer disease called "plaque-only type." The genealogic records of the kindred extend back to 1670. We constructed a family tree of 1403 individuals and identified 4 living demented members of the Johann F. kindred. The pedigree is consistent with an autosomal dominant trait. The analyses of known dominant dementia genes (APP, PS1, PS2, PRNP, and BRI) failed to reveal mutations in the proband. Further examination of this family might yield new insights into the genetics of Alzheimer disease.