Dementia incidence is linked to a single gene variant, according to a study
Variations in a single gene have been identified as an under-recognized target for dementia therapies. The APOE gene has previously been identified as having a strong association with the commonest form of dementia, Alzheimer’s disease. However, statistical modelling by the UCL team, focussing on combinations of the gene’s most common allele variants, provided further evidence of how it might impact dementias. The gene has three common allele variants – ε2, ε3, and ε4 – with all individuals carrying two APOE genes in one of six possible combinations. It was established as early as the 1990s that people with one or more 4 APOE alleles had a higher risk of developing Alzheimer's disease than people with two copies of the more common 3 allele. Likewise, ε2 carriers were at less risk compared to ε3 carriers. Based on their modelling, the researchers estimated that 72-93% of Alzheimer’s cases would not have occurred without the presence of ε3 and ε4 alleles of the APOE gene. They added...