12. Does antigeria represent decelerated aging?

Antigeria is used here to denote cases wherein age-related failure is delayed and age-dependent mortality acceleration is suppressed due to the extension of development. Like progerias which are caused by single mutations, there are single mutations (e.g. in the growth hormone pathway) that can decelerate aging (deleteriome growth) by delaying development. There is also an extremely rare genetic condition (syndrome X in humans) that results in asynchronous development of organs, leading to early mortality. Antigeria may be also understood at the level of species when their growth continues well after the onset of reproduction. Examples include species or conditions with non-Gompertzian aging, neoteny (e.g. the axolotl) and indeterminate growth (e.g. some fishes and tortoises).