A new study further illustrates that when it comes to risk of Alzheimer's disease, even genetically determined forms of the disease, genetics is only one piece of the puzzle. Researchers investigated the influence of genetics and educational attainment on cognitive decline by studying data from 675 people who carry a mutation that predisposes them to early onset Alzheimer's disease. Carriers of this mutation -- known as PSEN1 E280A -- have a median age of 49 for onset of dementia. The team found that among carriers who also carried a second mutation that puts them at heightened risk -- APOE e4 -- had an accelerated age of onset of cognitive decline. Among carriers who had an APOE e2 mutation -- known to be protective -- age of onset was delayed. The team also assessed the effect of educational attainment on cognitive function among PSEN1 E280A mutation carriers, including those who carried different APOE genotypes. They found that higher educational attainment -- that is, more years of education -- was associated with preserved cognitive ability particularly for those at highest genetic risk.
