Posted on 12/15/2011 10:00:15 AM PST by Pharmboy
COLUMBUS, Ohio – A new study has identified a gene mutation that researchers estimate dates back to 11,600 B.C., making it the second oldest human disease mutation yet discovered.
Researchers with the Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute led the study and estimate that the mutation arose in the Middle East some 13,600 years ago. Only a mutation seen in cystic fibrosis that arose between 11,000 and 52,000 years ago is believed to be older.
The investigators described the mutation in people of Arabic, Turkish and Jewish ancestry. It causes a rare, inherited vitamin B12 deficiency called Imerslund-Gräsbeck Syndrome (IGS).
The researchers say that although the mutation is found in vastly different ethnic populations, it originated in a single, prehistoric individual and was passed down to that individual’s descendents. This is unusual because such “founder mutations” usually are restricted to specific ethnic groups or relatively isolated populations.
The findings were published recently in the Orphanet Journal of Rare Diseases.
“Diagnosing IGS is often time-consuming and inconclusive mainly because vitamin B12 deficiencies have many causes, so identifying this condition usually involves excluding other possibilities,” says principal investigator Stephan M. Tanner, research assistant professor of molecular virology, immunology and medical genetics.
“Our findings permit reliable genetic diagnostics in suspected cases of IGS in that this mutation should be considered first when genetically screening patients from these populations.”
Even in rare disorders, founder mutations can cause a significant fraction of all cases, he says. This mutation accounts for more than half of the cases in these populations and for about 15 percent of cases worldwide. “It is also often seen in expatriates living abroad,” Tanner says.
IGS was identified just over 50 years ago. It occurs in children born with two mutated copies of either the amnionless (AMN) or the cubilin (CUBN) gene. When a genetic mistake is present in both copies of either of these two genes, a person cannot absorb vitamin B12 in the small intestine, resulting in the deficiency.
Children with IGS experience a high risk of infections, fatigue, attention deficit, paralysis and, ultimately, a form of anemia that can be fatal if left untreated. An estimated 400 to 500 cases of IGS have been described worldwide thus far. The incidence rate remains unknown. The syndrome is treatable with life-long injections of vitamin B12.
For this study, the researchers examined a total of 20 patients, 24 parents, 8 unaffected siblings, and 4 grandparents from 16 IGS families. Because the researchers found the mutation in such diverse populations, they were unsure whether it was a true founder mutation that first arose in one individual and was passed down through many generations, or whether it was simply a mutation that recurred frequently over time in different populations.
Careful analysis of the gene sequences on either side of the mutation (i.e., the haplotype in both the Muslim and Jewish families), however, pointed to a single mutational event rather than repeated events.
Funding from National Cancer Institute helped support this research.
Other researchers involved in this study were Cameron M. Beech, Sandya Liyanarachchi, Nidhi P. Shah, Amy C. Sturm and Albert de la Chapelle of Ohio State University; and May F. Sadiq of Yarmouk University, Jordan.
The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (cancer.osu.edu) strives to create a cancer-free world by integrating scientific research with excellence in education and patient-centered care, a strategy that leads to better methods of prevention, detection and treatment. Ohio State is one of only 41 National Cancer Institute (NCI)-designated Comprehensive Cancer Centers and one of only seven centers funded by the NCI to conduct both phase I and phase II clinical trials. The NCI recently rated Ohio State’s cancer program as “exceptional,” the highest rating given by NCI survey teams. As the cancer program’s 210-bed adult patient-care component, The James is a “Top Hospital” as named by the Leapfrog Group and one of the top 20 cancer hospitals in the nation as ranked by U.S. News & World Report.
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For additional information, see the 2011 review paper about IGS written by Ralph Gräsbeck – one of the two original describers of the syndrome in 1960 – and Stephan Tanner.
Contact: Darrell E. Ward, Medical Center Public Affairs and Media Relations, 614-293-3737, or Darrell.Ward@osumc.edu
What does that have to do with whether it is a useful mutation?
One way that they date the change is to look at the genetic similarities between populations and see how much and where they differ. Geneticists use an observed and measured "molecular clock" which helps pinpoint the timing. Click here if you want to learn more about this.
Indeed...you raise an excellent point. There is really no rule other than a numbers game to determine what is the “normal” gene and what is the “mutation.” If a population is all blue-eyed (and just for this example let’s just assume for a moment that eye color is based on one set of genes) and a change in the blue eye gene occurs and an individual is born with brown eyes, then that is the “mutation,” whereas in other populations the brown eye is normal and the blue would be the mutution.
I was just wondering about the relevance of “second oldest” and thought I would ask you. I did get an answer. Thanks, though.
The example I cited is far, far older than the one this article is based on.
I think (and there I go thinking again...) the "second oldest" the author meant was the second oldest in humans all the mutations, sections an genetic fine tuning that lead up to "human" doesn't count, at least in his mind.
Glad you got a satisfactory answer, and I think I just might owe you an apology for for assuming you were one of those people!
First of all, the word "evo" is a term of derision which translates roughly as: "since I hate science and can't argue with facts and reason, I'll just call you nasty names."
Second, to answer your question: over the long period of four billion years, all DNA codings were once mutations from whatever came before.
Useful mutations survived, multiplied and so became standard in following generations.
But the rate of DNA mutations is quite small -- maybe one per generation -- and most are not helpful.
Finally, computer comparisons of different DNAs from around the world can show which mutation-changes are relatively recent and which more ancient.
Evo is simply short for evolutionist which nobody wants to take the time to write out fully every time used. If you take it as an insult I cannot help that. I will refer to Republicans as Repubs and certainly am not insulting all Republicans. Second, you were extremely insulting with your comment: "First of all, the word "evo" is a term of derision which translates roughly as: "since I hate science and can't argue with facts and reason, I'll just call you nasty names." It seems that clearly you are doing the exact thing you accused me of doing in triplicate so who is reverting to name calling instead of logic? And who is judging somebody's heart saying that someone hates science just because they do not agree with you? I love science.
Finally, computer comparisons of different DNAs from around the world can show which mutation-changes are relatively recent and which more ancient.
What perimeters do they base their comparisons on or do we simply trust them blindly. I prefer to know the basis, or assumptions, that analysis are built upon. There is a lot of fraud out there in the scientific community as well as in almost every other aspect of society today. In case you haven't noticed we are being scammed on all different levels of society today. People in academia have a lot of motivation to falsify their data in order to get acceptance by others in their fields, grants, prestige, and advancement, plus they may be just ill informed by previous false but highly accepted assumptions.
Just look at what is perpetrated in the name of science when it comes to the green house agenda if you want to know the kind of thing I am referring to. Since this view is the view promoted by academia, for whatever reasons, then data that supports green house warming is pushed through the system, even if changing that data is required while data that doesn't support the promotion of the warming of the planet is summarily left out. Those who do not go along with the status quo are not promoted, loose their grants and may even be, if not tenured, let go. The system is set up to keep the lie going, excluding the truth at every level. Those that do not believe that the green house effect is ruining the environment keep their mouths shut if they want to be accepted by academia.
The informed see the same kind of thing happening at many levels of society and in all kinds of fields of study. It happened starting many years earlier concerning the theory of evolution and this false theory has become even much more extremely entrenched in academia then the green house effect has even begun to be. It is a irrefutable "fact" to many of those who have been indoctrinated since their early childhood to believe in it. Only by an act of clarity from Almighty God can those so indoctrinated ever be expected to escape from it. Hate evolutionist? No I don't hate evolutionist, I pity them as victims of a system of propaganda exceedingly hard to escape out of. After all, I use to be an atheist who thought evolution was fact myself. I didn't stop believing in evolution because I became a Christian but rather before I became a Christian based upon a search into fact.
The term "evo" is typically used by people who hate science, while pretending otherwise.
Bellflower: "What perimeters do they base their comparisons on or do we simply trust them blindly.
I prefer to know the basis, or assumptions, that analysis are built upon."
In fact, you condemn blindly what you've made no serious efforts to understand.
DNA analysis is cutting edge and state-of-the art in computing, mathematics and other technologies.
It has been used over 25 years now, for everything from establishing a child's paternity, to convicting murderers, to unraveling the travels and evolutions of families, tribes, breeds and species of many of Earth's genomes.
You can study DNA analysis in books and in college courses.
The best and the brightest among us make their careers -- in routine (i.e., paternity) to advanced research (i.e., teasing Neanderthal genes out of old bones).
How valid is DNA analysis?
First of all, we know they've been getting better at it over the years.
Work which once took months and years is now done in hours and days.
Second, we know DNA is often used to both convict the guilty and free innocents from jail.
So that tells us it's considered not only scientifically sound, but also legally valid.
Third, the results of DNA analysis of such things as human migration over the Pacific ocean have been confirmed by archaeological examinations.
Is DNA analysis ever wrong?
Of course -- if done improperly we can see situations like that young woman in Italy falsely convicted of murder.
But does that example make the science itself invalid?
No.
Bellflower: "In case you haven't noticed we are being scammed on all different levels of society today.
People in academia have a lot of motivation to falsify their data in order to get acceptance by others in their fields, grants, prestige, and advancement, plus they may be just ill informed by previous false but highly accepted assumptions."
Alleged anthropogenic global warming being a good example.
But does that imply every branch of science which you personally don't like is necessarily corrupt?
No.
The validity of DNA analysis -- the science and technology, if not every result -- is at this point beyond reasonable dispute.
Bellflower: "I didn't stop believing in evolution because I became a Christian but rather before I became a Christian based upon a search into fact."
You didn't "search into fact", you bought into a pack of anti-science propaganda.
Bellflower: "It is a irrefutable "fact" to many of those who have been indoctrinated since their early childhood to believe in it.
Only by an act of clarity from Almighty God can those so indoctrinated ever be expected to escape from it."
In fact, Almighty God has been absolutely clear in providing us with abundant, overwhelming evidence that evolution is the method He used to create the life we see today.
And this is not only the conclusion of science, it is also the teaching of most Christian churches.
So, "anti-evos" are a small minority in not only the overall population, but also amongst Christians.
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