Has anyone gotten a negative skin biopsy test but still seems to be a PD diagnosis, or a positive skin biopsy test without a PD diagnosis?

According to the initial testing, the skin biopsy test was positive in 92.7% of people confirmed to have PD, and 3.3% of healthy volunteers with no indication of PD tested as "false" positive. There are alternate possible explanations, the lifetime risk of developing PD is roughly 2% for men and 1.3% for women so maybe some or all of these were actually developing PD and the test was actually seeing a problem developing before anyone knew.

There's some potentially important questions about these cases. The data is only 3-5 yrs old and I don't see any follow-up data. There's probably pretty few tests that have ever been done outside the clinical trial that came up negative, because it's too invasive to be a general screening test for people without symptoms.