In Science this week, a multi-institute team presents an RNA-sequencing analysis of more than 6,700 samples spanning 29 different normal tissues from roughly 500 people, finding that somatic mutations are present in nearly every tissue in the body. The researchers developed a computational pipeline — dubbed RNA-MuTect — that can detect somatic mutations from bulk RNA-seq data, and find that macroscopic clones can be found in many normal tissues. Sun-exposed skin, esophagus, and lung show a higher mutation burden than other tested tissues, suggesting that environmental factors can promote somatic mosaicism. Meanwhile, mutational burden was associated with both age and tissue-specific cell proliferation rate, showing that mutations accumulate over both time and number of cell divisions. Notably, normal tissue was also found to harbor known cancer genes and hotspots. GenomeWeb has more on this, here.
Also in Science, Columbia University bioethicist Sandra Soo-Jin Lee and colleagues discuss the importance of public trust to the success of precision medicine research, as well as the need for greater inclusion of traditionally underrepresented and excluded groups. According to the team, inclusiveness will require not only the participation of more diverse populations, but addressing questions "about how to describe, define, measure, compare, and explain inferred similarities and differences among individuals and groups." Given the early stage of precision medical research, the authors call for "empirical studies that enable assessment and modulation of research practices and scientific priorities in light of their social and ethical implications." They also highlight the importance of multidisciplinary teams that include social scientists, ethicists, and policy-makers who can identify and help to implement practices that respect the histories and concerns of diverse publics."