By my read she had only a passing knowledge of the gene as any researcher in her field would before a colleague suggested it might be worth looking at and she confirmed a single nucleotide mutation and started to study the gene in more depth.
I'd worry that this was somehow acquired rather than just random. If it is exceedingly rare, I always worry it isn't a coincidence but rather a yet not understood method of transmission.
Possible, but unlikely. Single nucleotide changes to DNA are very common. Every single person born has multiple altered base pairs ("SNPs") and acquires more throughout their life (this is in part how cancer develops).
DNA is pretty interesting. It's kind of like reading a binary file in that every three base pairs constitutes a "codon" or the code for an amino acid, a building block of a protein. In this case, a base pair was knocked out via one of many unfortunate methods, and this causes a "frameshift error".
This is kind of like if you have an array of xyz vertices (common in 3d graphics) xyzxyzxyz and then you suddenly delete one: xzxyzxyz. If you try to read that file, you'll get unintelligible artifacts. Unfortunately, that's what happened to the little girl's gene. Depending on where the error occurs, more or less of the gene is read incorrectly. Sometimes if you're lucky, it occurs near the end and it might not be a big deal, but if it happens at the beginning or middle, the entire protein is messed up.
Anyways, I hope that helps illuminate what's happening here if you weren't already aware.
I'm not a professional biologist, but I sometimes act like one. Please correct me if I got a detail wrong. :)
EDIT: I should mention the reason why those changes don't hurt most people is that there's a lot of non-coding DNA that serves various functions such as structural, can promote the activation of other genes, could be part of disabled viral genomes, and then there's the fact that DNA is a degenerate code (some codons code for the same amino acid). There are probably many other categories that I didn't mention too.
Sure, spontaneous point mutations are very common. They account for many spontaneous abortions. But spontaneous point mutations in the Forkhead box G1 (FOXG1) gene are not very common. And scientists researching FOXG1 are also not very common.
But then, correlation is not causation. And this could well reflect selection bias.
And unless she was working with some vector carrying defective mouse FOXG1 genes, the probability that this particular defect would get transmitted is small.
I think your correct. 3 billion base pairs so with ~3 mutations per person it's 1/billion per child per location. But, lots of children (~2 per researcher and many researchers), lots of valid locations as researchers study many specific locations etc.
IMO, odds of something like this happening is fairly high.
PS: I don't think gender means anything here as the same story would get out if it was a male researcher.
It’s also not a random draw. Genes that have a significant impact on human development are the ones that cause disease - and by extension, draw the attention of researchers.
Shouldn't most corrupted files simply not get processed by the file system (and likely cleaned up by the immune system), especially if the error were at the beginning? It seems the mutation would need to be "close but wrong" to have the most truly devastating effects.
One example of "close but wrong" that is still very wrong would be a protein that isn't necessary for survival until you exit the womb. CF is like this, you don't breathe until you're born.
> I'd worry that this was somehow acquired rather than just random. If it is exceedingly rare, I always worry it isn't a coincidence but rather a yet not understood method of transmission.
Bad luck is bad luck--not everything has a controllable cause. 70% of all zygotes spontaneously abort.
The difference is that we would leave such children to die a century ago.
I don't know what the modern answer is for children with these kinds of debilitating errors in their DNA.
Yes, I get that feeling too. Not that is definately so but maybe possible, and hitherto not understood. "Impossible" hasn't fared well in medical or science history in general.
The birthday paradox arises because with N people, there are N^2 possible pairings of people for birthday collisions, and thus the number of people required for a collision scales as sqrt(D), an unexpected result.
But here, there aren't N^2 possible pairings since each researcher would still just be studying 1 gene. So this is really as surprising as the article claims.
As a molecular and cellular biologist in my previous life, I would say it is coincidence, although it is exceedingly rare, as you said. I don't see the possibility to acquire it, based on my understanding and training.
I want to provide some background, which is not typical, but pretty representative. In my 5~6 years as a biologists, I got my hands dirty extensively on 8~10 genes. It means I manipulated the genes in different ways via gene tools to try to figure out their properties. I knew every regions of these genes, even many single nucleotides, and what would happen if mutations occur at these nucleotides/regions. Other than that, I knew 50~60 genes very well. To this day, I can still remember most things about the genes. It is very sad that the random mutation happened to the lovely girl. If we only talk about statistics, the probability of the coincidence may be higher than we first thought.
