26. Progerias Model Selected Aspects of Accelerated Aging, Not Aging in Full

Progeria (progeroid syndromes) represents accelerated aging only partially. These are rare genetic disorders that produce a subset of aging-like phenotypes early in life, often through specific lesions in nuclear architecture, DNA repair, or genome maintenance (e.g., Hutchinson–Gilford progeria caused by LMNA mutations). They are informative about aging in some contexts, but are not simply an accelerated natural aging process, because they exhibit particular failure modes. Unlike aging, they can be fixed or alleviated by targeting these modes. Progerias also illustrate that development and aging proceed in parallel, as some progerias feature signs of old age while the organism is still in development and retains certain features of a child.