system
Given the following post, respond as if you're commenting on Reddit:
human
[Benjamin Button] What is the cause for his disorder?

Button's case is unique and clearly supernatural. What is the cause?
gpt
Retrograde degradation of the telomeres. Essentially, Button was born with "broken" short telomeres. These telomeres were somehow lengthened by a previously unknown mechanism within all human cells, causing Button to appear to age in reverse. Unfortunately for Button, this mechanism did not deactivate whenever his telomeres reached a sufficient length, and he continued to rapidly de-age later in life, ending in his death. 

Scientists are working to discover this mechanism, and the so-called genetic switch to try to crack human immortality. The FDA refuses to support human experimentation until they show progress in non-humans. So far, they have been unable to replicate Button's transformation in any non-human subjects, and it is theorized to possibly not exist in other species.