In a near-future sci-fi world, I described a disease with the following characteristics:
- Affects human female children (not necessarily exclusively).
- Is a neurodegenerative or similar disorder, leading to progressively reduced mobility.
- Can occur as the result of a chance mutation in the genes of an afflicted person in the early embryonic stage.
- Could lead to a girl of age 5 to occasionally (or more frequently) require a wheelchair for mobility.
- Is not curable or able to be mitigated significantly as of the present day.
- Can leave the afflicted person's cognitive functions relatively unimpaired, at least until after the age of 5.
- Leads to a greatly reduced lifespan, and can be expected to result in death between the ages of 10 and 30.
Does this describe any real-world disease? If so, which best fits this description?
The setting is a Shadowrun RPG game, set in 2075. The girl in question was 5 years old when her illness led her parents - who were top researchers in the field of cybernetics - to subject her to an experimental invasive treatment where her brain was removed from her body and enclosed in a life-support shell while nanites read the state of each neuron, created an artificial duplicate and removed the original, effectively remaking her into an inorganic consciousness. Very Ghost-in-the-shell like.
When it became apparent that a megacorporation perceived by her parents to be hostile was about to stage a hostile takeover of the parents' smaller corporation, her parents had her mind-shell placed in a simulation run at 100 times normal speed, allowing her to mature (the neuroreplacement technology allows this, it wasn't possible for earlier versions) to adulthood in 2 months, so that when the megacorp takes over, she is no longer a child, but an adult, her mind-shell placed into a cybernetic body powerful enough to allow her to defend herself.
The nature of this question is effectively, "What disease would be sufficiently terrible that loving parents would do this to their daughter rather than use some far less invasive method of treatment?".
I thought of some sort of neurodegenerative disease, on the justification that even replacing the entire body but leaving the brain untouched would likely be seen as an incomplete cure by her perfectionist parents. They don't just want to mitigate the disease that's killing their daughter by inches, they want to eradicate it so that she can become completely independent.
It may be that the disease occurred as a mutation in the girl, or that her parents are carriers. Either would work.
A very important point is that the girl must not be significantly mentally impaired at the age of 5. Later mental impairment is allowable, since it would give a good reason to replace her neurons... but it is not strictly necessary, as her parents may have been considering the accelerated maturation as being worth the additional risks.
Finally, to address the potential duplicate... The disease affecting the girl in my description may be a variety of cancer. My main criterion is actually the absence of mental impairment as of age 5.