A woman who noticed a change in her husband’s scent brought about by Parkinson’s disease has prompted researchers to begin working on a diagnostic test for Parkinson’s based on potentially odorous chemicals on the skin, according to UPI.

“It wasn’t all of a sudden,” Joy Milne told the BBC in an interview about her experience. “It was very subtle – a musky smell.” She began to notice a change in the smell of her husband, Les, six years before he was diagnosed with Parkinson’s disease.

Parkinson’s is a progressive nervous system disorder that gradually effects movement. There is no cure, and diagnoses are difficult.

After joining the charity Parkinson’s UK, Milne noticed that others affected by the disease carried a similar scent. This lead to researchers at Edinburgh University designing a study to test her ability.

Researchers hope that a detectable smell might assist in finding the disease’s molecular signature, leading to a swab test that would allow for a simple diagnostic test.

In the study, 6 people who have Parkinson’s and 6 people who do not were told to wear a t-shirt for one day before returning it for use in the study. The 6 shirts worn by those affected by Parkinson’s were identified by Milne.

Additionally, she identified one of the participants without Parkinson’s as having the disease. The man was diagnosed with Parkinson’s eight months later.

“It’s very early days in the research, but if it’s proved there is a unique order associated with Parkinson’s, particularly early on in the condition, it could have a huge impact,” Dr. Arthur Roach, director of research at Parkinson’s UK, told The Independent. “Not just on early diagnosis, but it would also make it a lot easier to identify people to test drugs that may have the potential to slow, or even stop Parkinson’s, something no current drug can achieve.”