Quantifying mutations in healthy blood
Menée à partir de données de séquençage de l'ADN de cellules sanguines issues d'environ 50 000 personnes et en appliquant la théorie génétique des populations, cette étude analyse l'évolution au cours du vieillissement des mutations génétiques de différentes populations de cellules sanguines et examine la façon dont certaines mutations peuvent conduire à l'expansion de certaines lignées clonales, à la diversité génétique des cellules normales ou au développement de cancers hématologiques
Over time, somatic mutations accrue during normal cell division and tissue self-renewal. The patterns of age-associated somatic mutation have been perhaps most extensively characterized in the blood. Although many mutations are functionally benign, a subset represents premalignant initiating events in hematopoietic stem cells that result in clonal expansion. This clonal hematopoiesis confers an increased risk of hematologic malignancy (after the accrual of additional cooperating mutations), as well as cardiovascular disease and overall mortality (1). On page 1449 of this issue, Watson et al. (2) investigate the clonal architecture and evolutionary dynamics of healthy blood by analyzing targeted DNA sequences of ∼50,000 blood cancer–free individuals. They find that positive selection for beneficial mutations, rather than neutral genetic drift, dictates the genetic diversity of normal blood. The identification of mutant clones and their associated fitness benefits could improve disease risk stratification.
Science , commentaire, 2019