They carry genetic defects that should have killed or disabled them long ago. But they defied the odds to live on and fight on. Not only did they survive the fatal genetic flaws, but they also hold the clues to defeating fatal human diseases, just as they have.
These are not people like you and me. These are genetic super heroes. They carry genes that are one in several hundred million. Technically, people like them are not supposed to be alive. But strange quirks of biology have allowed them to survive and they are using this good fortune to help millions of others in their fight against various diseases.
There are approximately 26,000 genes in the human body regulating functions from determining your hair color to the most intricate functions of your liver. Nature in its wisdom provided two copies of each gene, though no one really knows why, some other animals have 3 or even four copies of the same gene.
Genes are like a pack of cards. One set of cards (genes) is received from father and the other from mother. If both the copies of the same gene are good ones (normal biological function), then you are good. If one of them is bad, then you are still good, because the good one will cover for the bad one. But if both of them are defective, then that’s not a good thing. Think of genes like a pair of kidneys. People can make do with one kidney, but if both are bad, then they have to go for dialysis.
People who marry within families have a high probability of receiving both defective copies, if there are many defective copies floating within the family or a closely marrying community. As an example, if there are many two’s in a deck of cards, the the probability of pulling a two from the deck is higher. Similarly, if there are many defective carriers in the family, then the probability of defective being passed on to the child when two defective carriers marry is very high. This is the reason why consanguinity is discouraged. In some cases, a gene is completely absent, a condition known as knockout.
In mice, scientist can deliberately remove a gene to study what happens to the health of the mice when that gene is removed, a process known as “knocking out” the gene. They do this to study the critical functions of particular genes. However, humans won’t allow scientist do such things to them, not at least wilfully. Hence, the only recourse is to find natural human knockouts, an anomaly created by nature.
Already these individuals have made considerable contribution to science. The following are a few examples
- The development of the new cholesterol drug known as PCSK9 was based on discovery that some individuals have abnormally low LDL cholesterol levels. While investigating the cause, scientist found that these individuals lack a protein called PCSK9 and if this protein can be injected into anyone’s body, their cholesterol will drop. This is precisely what happened in clinical trials
- A recent study discovered a small fishing community in Pakistan which completely lacks the APOC3 gene (APOC3 knockout). For these individuals consuming high fat diet does not increase their triglycerides. Thanks to the discovery of this community, new drug development targeting this gene can help millions of people suffering from heart disease in future.
- Animals that lack the Myostatin protein have significantly higher proportion of muscle than those whose bodies produce this protein. Human knockouts are extremely rare, but their discovery can lead to the development of drugs for muscle wasting disease.
There are other such examples and scientists are only getting started and hope to develop drugs and therapies for many disease by studying these rare human super heroes and analyzing how they survived, against many odds. This learning can help defeat many diseases and help millions live a healthy life.
I will leave you with a thought – are you a knockout? Do you have a hidden gene secret in your genome? If so, you can save millions of people from potentially life threatening conditions. Be a hero and find out your genetic secrets that could save humanity.