Washington: The declining brain function that occurs during the normal ageing process is influenced by genes, a new study has found for the first time. "Identification of genes associated with brain ageing should improve our understanding of the biological processes that govern normal age-related decline," said John Blangero, a Texas Biomed geneticist and the senior author of the study. In large pedigrees including 1,129 people aged 18 to 83, the scientists documented profound ageing effects from young adulthood to old age, on neurocognitive ability and brain white matter measures.

White matter actively affects how the brain learns and functions. Genetic material shared amongst biological relatives appears to predict the observed changes in brain function with age. Participants were enrolled in the Genetics of Brain Structure and Function Study and drawn from large Mexican Americans families in San Antonio. "The use of large human pedigrees provides a powerful resource for measuring how genetic factors change with age," Blangero said. By applying a sophisticated analysis, the scientists including David Glahn, an associate professor of psychiatry at the Yale University School of Medicine, demonstrated a heritable basis for neurocognitive deterioration with age that could be attributed to genetic factors. Similarly, decreasing white matter integrity with age was influenced by genes. The investigators further demonstrated that different sets of genes are responsible for these two biological ageing processes.