A peer-reviewed genetic analysis has identified 48 previously unreported regions associated with Alzheimer’s disease risk, bringing its total to 127. The findings connect risk signals with both brain immune cells and neurons. The observational study also raises the estimated contribution of common genetic variants, while its ancestry imbalance limits conclusions across populations.
A peer-reviewed observational study of Alzheimer’s disease identified 48 new genomic regions associated with risk. Researchers found 118 regions in an analysis combining ancestry groups and nine more in ancestry-specific analyses, for a total of 127. A risk-associated region points researchers towards relevant biology; the association itself does not establish which gene is involved in a disease process.[1]
The analysis brought together 30 cohorts, including 109,479 diagnosed cases and 74,141 proxy cases. Proxy cases were genotyped people reporting an affected parent. Researchers estimated that common genetic variants contribute 16 per cent of disease liability, compared with earlier estimates near 5 per cent. Risk signals were enriched among genes more active in microglia, the brain’s immune cells, and less active in neurons in affected tissue.[1]
European ancestry represented 91 per cent of the effective sample, African ancestry 5 per cent and East Asian ancestry 3 per cent. Each other group contributed less than 1 per cent. That imbalance limits claims about equal predictive performance across populations. The findings nominate potential drug targets for further research; they do not demonstrate patient benefit from a new treatment.[1]
