Genetic disease amongst the Plain community

The purpose of this review is to highlight recent genetic studies of the Amish and Mennonite (Plain) communities. For decades, the study of genetically isolated populations has improved our understanding and management of genetic diseases that affect all populations.

Major themes of current genetic research of the Amish and Mennonites include new causative gene and new candidate gene discovery, phenotype expansion of previously identified genetic disease, and a target for AAV9-mediated gene therapy. Additionally, several genome-wide association studies (GWAS) examining complex traits such as dementia, cardiometabolic disease, and age-related macular degeneration have been conducted. Finally, clinically relevant studies of attitudes of the Plain community towards genetic testing and telemedicine, as well as reviews of and management suggestions for the Amish variants of propionic acidemia and APOB -associated familial hypercholesterolemia have been recently published.

Recent genetic studies of the Plain community continue to highlight the value of studying isolated populations to propel genetic disease discovery and treatment. Additionally, population-specific polygenic risk scores are needed for underrepresented and minority populations, to avoid exacerbating disparities in medical genetics care. Finally, it is important for clinicians to develop management guidelines for variants common in this rapidly growing population, such as propionic acidemia.