In the small town of Maplewood, a mysterious illness swept through the community in the spring of 2020. The residents decided to isolate themselves to prevent the illness from spreading. After several months, when they reopened their town, it was found that about 80% of the population had succumbed to the illness. Interestingly, around 20% of the residents survived, and many of them were found to have a unique genetic mutation known as gamma 45. One notable survivor, John Smith, lost his wife and three children to the illness but remained healthy throughout the outbreak. Researchers later discovered that many descendants of the survivors from Maplewood carry the gamma 45 mutation.

Which of the following, if true, most undermines the implications made within the passage?