In the world of Wolverine, Professor X and Magneto, mutants are feared and shunned.
“In our world, mutants are Olympic athletes and brilliant musicians and everyday people like you and me,” said Oklahoma Medical Research Foundation scientist Chris Sansam, Ph.D. “They’re actually so common that someone without any mutations would be the real anomaly.”
To understand mutants, it’s important to know a little about genetics, he said. Almost every cell of the human body has a nucleus containing thousands of genes. Genes are grouped into structures called chromosomes, and humans have 23 identical pairs in each cell. Add up all those chromosomes and you get deoxyribonucleic acid, or DNA.
DNA is made up of sugar, phosphate and four kinds chemical bases — adenine, thymine, cytosine and guanine. Add up all those genes and you have a lot of DNA. In fact, there are about 3 billion base pairs in a single set of human DNA.
“The order of those four chemicals is what makes us individuals,” Sansam said. “Their sequence in genes determines things like hair color, height, susceptibility to certain diseases and so much more. Why do children look like their parents? It’s in the genes.”
So what are mutations? Mutations are permanent changes to the DNA, whether in a single base pair or an entire chromosome. Different changes have different consequences, just as different X-Men have different powers.
“We inherit mutations from our parents and they happen throughout our lives,” he said. “Every time a cell divides to make a new cell, your DNA is copied. If the DNA has been altered, that change is passed on to every cell made from that line.”
Some mutations are passed down from parents, but others, called de novo mutations, occur in the sperm, egg or embryo. The earlier a mutation occurs in human development, the more its effects spread. Recent research has shown the average person has 74 de novo mutations in their DNA.
“That might seem like a lot, but remember that we’re talking about billions of base pairs,” said Sansam. “Many mutations have no readily apparent effects, though others can be quite serious.”
A mutation in the TP53 gene, for instance, might cause Li-Fraumeni syndrome, which drastically increases the chances of developing cancer.
Researchers are now beginning to truly understand mutations, because the science of genetic sequencing has only recently progressed to the point where DNA can be tested against parents and other family members, he said.
“We’re at the beginning of a wide-open frontier of new discoveries,” he said. “It may not seem as exciting as firing laser beams from your eyes to fight flying robots, but as a basic researcher, I can’t wait to see what the future holds.”
Greg Elwell is a public affairs specialist for OMRF.