Joy Milne, 72, is a retired nurse from Peth, Scotland. She also has hereditary hyperosmia—she's a "supersmeller." After noticing that her husband's natural scent had changed, she eventually determined that the shift in odor was a very subtle early symptom of Parkinson's disease. Since then, Milne has collaborated with UK scientists to create an experimental skin-swab test to detect the molecules that deliver the signature smell of Parkinson's. From Scientific American:
Parkinson's may not be the only disease Milne has a nose for. She's also reported noticing a unique smell in people with Alzheimer's, cancer, and tuberculosis and is working with scientists to see whether a specific olfactory signature of those diseases can be deduced.
For Milne, the hope is that this work will ultimately benefit patients with these conditions. "My husband suffered from [Parkinson's] for 21 years after his diagnosis, but he had it many years before that," Milne told Scientific American in 2015. "I would like to see that people don't suffer the way he suffered."
(Thanks, Jeff Cross!)