2. Genetic Causes are Rare
A 2015 article from the Independent in the UK about research into congenital insensitivity to pain notes that it only affects about 1 in 1-million people. It says that scientists studying the condition were looking at only 11-affected families in Europe and Asia but have identified mutations in a gene called PRDM12.
The researchers found mutations in both copies of the gene that a person with the condition has inherited from their mother and father, who themselves have no symptoms of the defective gene, it adds. Those with congenital insensitivity to pain have their pain sensors “turned off from birth” and therefore will never know physical pain, explains the article.