They say that these healthy individuals could provide hints at how to suppress the onset of genetic diseases, but it is impossible to track down these 13 individuals because the original studies they took part did not obtain consent for them to be re-contacted.
'I would guess that most of the public when they hear the word mutation, would say: equals bad, equals risk. Some of them are bad, we know that. But I think the concept that mutations could be beneficial gives a reason to look at individuals who are normal and try to find ways of prevention,' said Dr Stephen Friend of the Icahn School of Medicine at Mount Sinai, New York, and Sage Bionetworks, who led the research.
The researchers, who published their results in Nature Biotechnology, searched 589,306 genome sequences from 12 past and ongoing studies – including the UK10K Project, the 1000 Genomes Project and data from 23andMe. They homed in on 874 single-gene mutations that cause 584 distinct childhood diseases, such as cystic fibrosis.
The search identified 15,597 individual genomes, which was then narrowed down to 303 healthy candidates who appeared to be 'resistant' to the disease-causing mutation they were carrying, according to self-reported medical information collected alongside the genome sequences.
Each of the 303 individual's medical records were analysed for symptoms of the predicted disease, narrowing the list of candidates to 13 healthy individuals spanning eight distinct genetic disorders. These genetic disorders were severe and typically manifested in childhood, so the complete absence of any symptoms suggested truly 'resistant' individuals. Only a portion of the genetic information was available for these individuals, so the research team was unable to look for compensating mutations elsewhere in their genomes that might explain this resistance to disease.
Unfortunately, the original studies that collected the genomic data from these 13 people did not include a re-contact clause, so the researchers can't track them down to sequence their whole genome or to determine whether the results are in fact correct. It is possible that the results are simply a result of incorrect reporting of symptoms in the original studies.
Knowing that these resistant individuals might exist has prompted Dr Friend and colleagues to continue their search. They have launched The Resilience Project to attempt to find more genetically resistant individuals to study. 'We now have tools that allow us to search for people who should have gotten sick, among normal individuals. Finding those individuals is a starting point for searching for other changes in the genome that might give us clues to deliver therapies. So: study the healthy. Don't just study the sick,' said Dr Friend.