As a follow up to my Alien Hand Syndrome post, a similar condition. This one could explain why a character might have gotten a cyberlimb.
I'm not posting this as a negative quality, as it's so easily countered. In fact, by 2075 replacement of the alien limb with a cybernetic might be an accepted procedure.

A similar, and likewise bizarre, condition is known as Body Integrity
Identity Disorder (BIID), which appears to be purely psychological. People
suffering with this condition also feel as if one of their limbs is not
really a part of themselves. But rather than live with it, they have a very
strong desire to have the offending limb amputated. As psychiatrists
describe it, the "motivation for the preferred body modification is believed
to be a mismatch between actual and perceived body schema." Not included in
the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV), most
with this condition receive little to no formal treatment; rather, many take
matters into their own hands:

When he was just out of college, he'd tried to [amputate his leg]
using a tourniquet fashioned out of an old sock and strong baling twine.
After two hours the pain was unbearable, and fear sapped his will.

The leg was always there as a foreign body, an imposter, an

He spent every waking moment imagining freedom from the leg. . . .
The leg just wasn't his. He began to blame it for keeping him single.

Another BIID sufferer had more success when he shot his leg. As he said,
"I've wanted to be one-legged since I was a child . . . . No one can help
this overwhelming and irrational wish that I've experienced with varying
degrees for as long as I can remember. For the first time in my life, I'm
finally happy."

In a 2005 study, it was found that of 52 BIID sufferers interviewed, 9 had a
limb amputated and six of those used "methods that put the subject at risk
of death." Perhaps even more disturbingly, three had been able to find a
surgeon willing to amputate a healthy limb; in fact, in the 1990s, Dr.
Robert Smith of the Farkirk Royal Infirmary in Scotland performed at least
two such surgeries before news of them became public. Another surgeon, who
had lost his license years before, performed an illegal amputation of a
healthy limb in Tijuana in 1998, but, sadly, the patient died of gangrene.
Today, there is apparently a surgeon somewhere in Asia who, for $6,000, will
sneak a BIID sufferer into his hospital and perform an emergency amputation
while pretending to do another surgery.