[Asn23]-beta-Amyloid (1-42), Iowa mutation, is a biologically active peptide with increased aggregation propensity and fibril toxicity. This mutation involves the substitution of Aspartic acid (Asp) at position 23 with Asparagine (Asn), contributing to autosomal dominant Alzheimer's Disease and associated with severe cerebral amyloid beta-protein angiopathy (CAA) due to a missense alteration at position 694 of the amyloid precursor protein (APP) gene.