Former NFL players Wayne Clark and Fred McNeill participated in a UCLA study . The protein mutation , due to a brain disease , was found in both of their brains . Clark started playing football in high school and was not a sought-after college recruit . Fred has early - stage dementia ; Clark does not . Researchers say other variables may come into play when it comes to the mutation .
Former NFL players Wayne Clark and Fred McNeill participated in a UCLA study . The protein mutation , due to a brain disease , was found in both of their brains . Fred has early - stage dementia ; Clark does not . Researchers say other variables may come into play when it comes to the mutation .