Lack of ethnic diversity in single-cell transcriptomics hinders cell type detection and precision medicine inclusivity.

Perhaps one of the most revolutionary next generation sequencing technologies is single-cell (SC) transcriptomics, which was recognized by Nature in 2013 as the method of the year. SC-technologies delve deep into genomics at the single-cell level, revealing previously restricted, valuable information on the identity of single cells, particularly highlighting their heterogeneity. Understanding the cellular heterogeneity of complex tissue provides insight about the gene expression and regulation across different biological and environmental conditions. This vast heterogeneity of cells and their markers makes identifying populations and sub-clusters especially difficult, even more so in rare cell types limited by the absence of rare sub-population markers. One particularly overlooked challenge is the lack of adequate ethnic representation in single-cell data. As the availability of cell types and their markers grow exponentially through new discoveries, the need to study ethnically driven heterogeneity becomes more feasible, while offering the opportunity to further elaborate ethnicity-related heterogeneity. In this commentary, we will discuss this major single-cell limitation particularly focusing on the repercussions it has on disease research, therapeutic design, and precision medicine.