(CNN) Finding your loved one a perfect gift can be hard. But a diamond ring, silk dress, or designer bag couldn't come close to Mike Nipper's gift to his wife of 51 years.

Mike donated his kidney to his wife, Peggy, after hers began to fail as a result of polycystic kidney disease (PKD). The genetic condition causes cysts to develop in the kidneys, often leading to kidney failure when the organ becomes too enlarged.

"It was quite a gift," Peggy told CNN. "I don't think he has to give me another gift for the rest of my life. This was the ultimate present."

Peggy lost her own mother to the same disease, and her brother, who also inherited PKD, has reached stage three kidney failure.

So when Peggy's kidney was functioning at just 14 percent, she only had two options: go on dialysis or get a transplant.

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