Familial late-onset Alzheimer's disease: description of an Italian family with four affected siblings and one case of early-onset dementia in the preceding generation

We describe a family composed of six siblings, four of which affected by late-onset Alzheimer's disease (LOAD). We constructed the family pedigree, evaluated mutations usually associated with early-onset Alzheimer's disease (APP, PSEN1, PSEN2), and assessed polymorphisms in the apolipoprotein E (APOE) gene and in cytokine genes that we had previously found to be associated with a higher risk of LOAD (IL-10, IL-6, TNF-α). Results showed that all subjects carried one ε4 allele of the APOE gene and those with the earliest age of onset exhibited the AA (-1082) IL-10 and the CC (-174) IL-6 genotypes. The only male had a genetic profile which also included the A (-308) TNF-α allele. These data confirm the role of the APOE gene as genetic risk factor in LOAD, and suggest that the risk of developing AD may be governed by a "susceptibility profile" involving polymorphisms in inflammatory genes.