A presenilin 1 mutation in an early onset Alzheimer's family: no association with presenilin 2.

Genes on four chromosomes have been associated with Alzheimer's disease. Mutations in the chromosome 14 gene (S182 or presenilin 1) have been linked with an aggressive very early form of the disease while mutations in a chromosome 1 gene (STM2 or presenilin 2) have been linked with Volga German kindreds. When we screened our Alzheimer's patients for the first mutations reported, we only found one in the presenilin 1 gene in an extended family with three affected siblings, all of whom had onset of symptoms in their 4Cs. ApoE and ApoCI genotyping indicated that these risk factors were not associated with the disease in this family. None of our patients with early or late onset disease had the mutation described for presenilin 2.