Influence of Genotype on Mortality and Cognitive Impairment.

While many studies have examined the associations between genotype and mortality, findings have often been conflicting and it remains unclear whether genotype affects longevity. Using selected individuals from the Manchester arm of the Brains for Dementia Research programme and University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age, we investigated relationships between genotype and age at death in both cognitively normal and cognitively impaired individuals. Results indicated that carrying the 4 allele led to a reduced chance in an individual reaching 80+ years and remaining cognitively healthy. Conversely, 2 carriers tended to live longer and remain cognitively normal. These findings add to the evidence that genotype influences longevity, especially in cognitively impaired individuals who carry the 4 allele.