Collection of genetic data in ethnic‐based studies across Aymaras, Quechuas and Mestizos: the challenges of the Genetics of Alzheimer’s in Peruvian Population (GAPP) study

Background The Genetics of Alzheimer’s Disease in Peruvian Population (GAPP) study aims to investigate genetic and environmental risk factors for Alzheimer’s Disease (AD) in Peru. The project is led by Columbia University (CU, New York, US) and the Instituto Peruano de Neurociencias (IPN, Lima, Peru). For the past year and a half, despite the ongoing COVID‐19 pandemic, the study has collected data on cognitive function, health, diet and numerous clinical and biological risk factors for AD. In addition, we collected blood samples for DNA extraction as well as serum and plasma to look at core AD biomarkers. Method Recruitment prioritized populations from south Peru, the Quechuas and Aymaras, because of their high proportion of Native American ancestry (or, in other words, low admixture with European ancestry) as well as Mestizo (mixed Native‐European ancestry). Three recruitment sites were established in Lima, Puno and Arequipa. Interviewers were trained to clinically and cognitively assessed the participants and collect and ship blood samples to the main site (IPN). DNA samples were then sent to CU for processing. Serum and plasma samples were processed in Lima and stored at ‐80C for batch shipping to CU. DNA samples were sent to CD Genomics and Children’s Hospital of Philadelphia for APOE genotyping and GWAS, respectively. Result A database with 350 participants has been created. Blood samples from all participants were collected; 268 successfully underwent GWAS and APOE genotyping. An additional 82 samples are pending QC and genotyping. No samples were dropped at extraction, and only 0.7% failed DNA quality standards for genotyping. Conclusion Sample collections for genetic studies in South American indigenous populations such as Peru represent important logistic challenges. The use of blood as a main source of DNA provides an effective and reliable source for genetic data analysis. Plasma and serum biomarkers will provide additional insights into the disease manifestations and validation of the clinical diagnosis in these underrepresented populations. Ongoing recruitment will augment the analytical power of the cohort by collecting blood, serum and plasma samples from additional GAPP participants.