Answer:
Test random people from the area and compare that to the national average.
Step-by-step explanation:
In order to prove right or wrong your theory, you would just need to see how many people is living in the area, and then take random samples of their DNA in order to make tests to see if they have extra copies of the STPN gene, if your results show that they do have more than the national average then you are correct and that could be it, if they don´t then you have to search for a different approach to the matter.