High fidelity DNA replication during each cycle of cell division is required to maintain genomic stability and prevent chromosomal mutations and rearrangements that can cause disease and aging. Mutations in ATRX, a gene that encodes a protein that participates in DNA replication, are associated with X-linked mental retardation, various cancers, and developmental disorders, but the cellular functions of ATRX are still unclear. In this issue of the Journal of Clinical Investigation, researchers led by Nathalie Bérubé at the University of Western Ontario report on the effects of Atrx deficiency in mice. Using neural precursor cells (NPCs) from Atrx-deficient mice, Bérubé and colleagues found that loss of ATRX is associated with increased DNA damage. Additionally, mice lacking neural Atrx exhibited systemic endocrine dysfunction, shortened lifespans, and degenerative phenotypes similar to human premature aging disorders. These studies demonstrate that ATRX plays a critical role in maintaining the integrity of cellular DNA.
