The Seattle Alzheimer's disease data set.

Forty families submitted to Genetic Analysis Workshop 8 are described. These are the families in the Seattle data set which have been typed for at least one genetic marker from the centromeric region of chromosome 21 or the q arm of chromosome 19. Thirteen of these families have average ages of onset below age 61 and are therefore considered to be early onset families. Seven of the families are of Volga German descent. Thirty-four of the families have autopsy documented Alzheimer's disease, including all 13 of the early onset pedigrees. The data set includes both the clinical and pedigree information available on the portions of the pedigrees used in the linkage analyses, genotype data on three loci on chromosome 19 and four loci on chromosome 21, and more extended family data on individuals who have not been included in the linkage analyses.