The question plaguing the geneticists about the Burns family was: how have they survived?
In 2016, several geneticists theorized that certain people may have a good-gene bad-gene scenario taking place on their chromosomes that has not yet been identified. According to an article published recently in STAT News, researchers searched over five hundred thousand genomes trying to find patients who had a serious childhood disease but never experienced symptoms.
Professor Stephen Friend at Oxford often quoted clinicians who said that they would never believe anyone would still be alive if they had “that mutation.”
Yet after searching the records of 589,306 people, the clinicians did find thirteen people who were medically “unbelievable.” However, when they searched again they were unable to find them or to locate the protective variants that were suspected of hiding among their cells.
Dr. Cecilia Low, Pittsburgh University’s developmental biology chair who headed the team of researchers, commented that the mutation was not survivable and if someone has it they are going to die.
It was almost by accident that professor Lo found eight other genomes that fit Dr. Friend’s earlier description. Her team retraced their steps looking for the mutation that could be saving the Burns family’s lives.
There were several variants shared by the eight genomes with some having a similar heart defect as the Burns family. However, one stood out to the researchers as being the protective variant.
When the researchers bred genetically modified mice with the two variants, the embryos in the mice survived.
About the Family
The Burns family lives in a rural area of Pittsburgh at the West Virginia borderline. Nicole Burns is employed at an assisted living home. Her daughter, Peyton, is an ardent hunter, and her son, Cameron, plays on a basketball team.
According to everything the researchers know about the Burns’ genome, it is so lethal that they cannot possibly have it – as they are very much alive and well.
Testing the Embryos
Over and over the Burn’s family’s genetic variant was inserted into the DNA of a mouse egg. But each time the sound waves bounced back indicating the embryos in the womb of the mouse were dead.
Nothing made sense. The pregnant belly of the mouse was repeatedly scanned, but although the ultrasound screen showed the embryos, they did not have a heartbeat. They were in the womb but were dead.
Then Dr. Lo thought about the possibility that the Burns family inherited a second rare mutation that prevented them from having the deadly effects caused by the first mutation. She initially thought it was improbable.
But the researchers went ahead and bred a new group of mice genetically modified with both variants, and the embryos survived.
Some of the embryos even had the same defect as the Burns family. In any event, the second variant proved to be protective.
To the researchers, it seemed like a scientific triumph. To Dr. Friend, it was a reminder about how far they had come in the past decade.