SUPERHEROES with powers that come from mutations in their genomes are, like the X-Men, a staple of comic books and movies. Now an extensive study of the genetics of more than 500,000 people has revealed a different kind of mutant superhero: a small number of individuals who seem to be perfectly healthy despite carrying in their DNA a mutation linked to a severe childhood disorder.
The 13 adults identified were found to have faulty genes associated with one of eight different inherited conditions. These included cystic fibrosis, a disease that interferes with breathing, and atelosteogenesis, which affects bone and limb development. People with the eight different genetic faults can die at birth or shortly after.