Amyloid-β1–43 cerebrospinal fluid levels and the interpretation of APP, PSEN1 and PSEN2 mutations

• Published in: Alzheimer's research & therapy 2020-09, Vol.12 (1), p.1-14, Article 108
• Main Authors: Perrone, Federica, Bjerke, Maria, Hens, Elisabeth, Sieben, Anne, Timmers, Maarten, De Roeck, Arne, Vandenberghe, Rik, Sleegers, Kristel, Martin, Jean-Jacques, De Deyn, Peter P., Engelborghs, Sebastiaan, van der Zee, Julie, Van Broeckhoven, Christine, Cacace, Rita, Goeman, Johan, Crols, Roeland, Dermaut, Bart, Ivanoiu, Adrian, Hanseeuw, Bernard, Deryck, Olivier, Bergmans, Bruno, Versijpt, Jan, Pharmaceutica, Janssen, Saido, Takaomi
• Format: Article
• Language: English
• Subjects: Age; Alzheimer mutations; Alzheimer's disease; Alzheimer’s disease (AD); Amyloid-β 1–43 (Aβ1–43); Biomarkers; Cerebrospinal fluid; Cerebrospinal fluid (CSF); Dementia; Deoxyribonucleic acid; DNA; Informed consent; Memory; Metabolism; Mutation; Older people; Oxford Nanopore Technologies (ONT) long-read sequencing; Patients; Peptides; Proteins; Software
• ISSN: 1758-9193; 1758-9193
• DOI: 10.1186/s13195-020-00676-5

Background Alzheimer’s disease (AD) mutations in amyloid precursor protein (APP) and presenilins (PSENs) could potentially lead to the production of longer amyloidogenic Aβ peptides. Amongst these, Aβ1–43 is more prone to aggregation and has higher toxic properties than the long-known Aβ1–42. However, a direct effect on Aβ1–43 in biomaterials of individuals carrying genetic mutations in the known AD genes is yet to be determined. Methods N = 1431 AD patients (n = 280 early-onset (EO) and n = 1151 late-onset (LO) AD) and 809 control individuals were genetically screened for APP and PSENs. For the first time, Aβ1–43 levels were analysed in cerebrospinal fluid (CSF) of 38 individuals carrying pathogenic or unclear rare mutations or the common PSEN1 p.E318G variant and compared with Aβ1–42 and Aβ1–40 CSF levels. The soluble sAPPα and sAPPβ species were also measured for the first time in mutation carriers. Results A known pathogenic mutation was identified in 5.7% of EOAD patients (4.6% PSEN1, 1.07% APP) and in 0.3% of LOAD patients. Furthermore, 12 known variants with unclear pathogenicity and 11 novel were identified. Pathogenic and unclear mutation carriers showed a significant reduction in CSF Aβ1–43 levels compared to controls (p = 0.037;