This is the not the first gene that researchers have connected to people's inability to feel pain, but this one works differently. In the study, researchers compared the genes of 11 people with congenital insensitivity to pain to their pain-feeling family members. Among those that couldn't feel pain, the researchers found 10 different mutations of PRDM12, a gene involved in neuron development. Basically, those mutations disrupt the way neurons grow, which could make it difficult for them to relay pain messages properly. When the researchers modified the gene's equivalent in frog embryos, the change disrupted the development of the frogs' neurons, indicating that it may do the same in humans.