Exome analysis of 22,319 individuals links extremely rare copy-number variants and 22q11.21 dosage to Alzheimer risk.

Rare copy-number variants and 22q11.21 dosage alterations significantly influence Alzheimer’s disease risk, with deletions increasing and duplications decreasing susceptibility.

• Why it matters: Understanding the genetic factors beyond known monogenic causes is crucial for uncovering the complex mechanisms underlying Alzheimer’s disease and identifying potential therapeutic targets.
• What they did: Analyzing 22,319 exomes, the study identified rare CNVs, especially in AD-related genes and the 22q11.21 region, using exome-wide and gene-set burden analyses, including replication in large cohorts.
• The result: Findings reveal that deletions in 22q11.21 increase AD risk, while duplications are protective, with SCARF2 overexpression reducing amyloid-β uptake, offering new insights into genetic modulation of Alzheimer’s disease.