Scientists found genetic mutations in every astronaut blood sample they studied | Hacker News Reader

Scientists found genetic mutations in every astronaut blood sample they studied

futurism.com

200 pointskiyanwang104 comments

This links to a (much better) better press release which in turn links to the original study.

https://www.newswise.com/articles/researchers-find-spaceflig...

https://www.nature.com/articles/s42003-022-03777-z.pdf

OP - and HN readers in general - please consider not submitting the first article you find on an interesting topic. Follow the links back and submit the best version you can find. You do not owe the clickbait outlet any sort of reward just because they promoted a bit of interesting news onto your radar. If there weren't so much clickbait, quality news would stand out much more easily.

Science writers, maybe you want to inform the public by making information simple and accessible to a general audience. That's good. But if you just give them factoids and don't include any scientific reasoning (like a comparison to the baseline, or noting the absence of one) then you're just selling sugary snacks that are not really very nutritious.

> If there weren't so much clickbait, quality news would stand out much more easily.

So much this. I took a break from some news websites a few years back, when I recently visited one of them, I was sad to see that many front page news articles had clickbait titles.

Somehow each generation is convinced anew that their pearl clutching will be of any interest to others

I agree with the sentiment of tracing a headline back to the topic's best coverage.

But posting plain studies directly to non-industry forums is often not ideal. The studies are not written for a general audience and rely on jargon, shorthand, assumptions, and shared education that general audience readers are at least as likely to misinterpret as professional science writers.

We like to beat up on science writers for writing poor and misrepresentative coverage of research, but are you sure a bunch of random (and often compulsively contrarian) intellectuals trying to earn internet points are an improvement?

The best of both worlds is probably to find the best coverage, and then add the study in a comment.

The GP said that you should submit the best article on any given topic, not just the original study. In fact, they specifically called out the press release by the original authors (which can be viewed on Mt Sinai's blog: https://www.mountsinai.org/about/newsroom/2022/fesearchers-f...) as being "much better" then the original article. I'm not a researcher, but as a member of the public I also agree that the press release seems to do a good job at explaining things for the public while also not dumbing things down or exaggerating the findings too much. Nobody is saying you should just post the original study devoid of any context

Totally. I wasn't challenging the GP, just elaborating on nuance.

>posting plain studies directly to non-industry forums is often not ideal. The studies are not written for a general audience and rely on jargon, shorthand, assumptions, and shared education that general audience readers are at least as likely to misinterpret as professional science writers.

I think there's an argument to be made that, regardless the specific subject of discussion, a forum like HN is not a "general" audience and can appreciate content that hasn't been watered down for the general masses.

Hacker News is beholden to witty titles

dang has said that HN doesn't outright ban TV news sites like CNN, despite being against the guidelines[0], because they do occasionally surface interesting stories.

But every example of that I've seen has essentially been blogspam that is better covered by primary sources instead. I really wish he'd reconsider.

[0] "If they'd cover it on TV news, it's probably off-topic." https://news.ycombinator.com/newsguidelines.html

That particular guideline seems to have informally expired. Normal news gets to the front page all the time. See, for example, the thread on the death of the queen. Hardly related to tech, startups, or even intellectual gratification.

I feel like it just gets waived every once in a while when the news is appropriately "important". The death of a monarch in a western nation essentially hits all the criteria of becoming massive media fodder.

I'm pretty sure the only thing that's interesting to talk about when the Queen dies is if this is a perfect time to get rid of the monarchy, and dang said that's too 17th century to talk about. Without that conversation, IMO what's happening in the lives of kings, queens, princes, and princesses is also too 17th century to talk about.

While I'm all for a Cromwell II to this Charles III, I don't think it's fair to say that there are no other interesting things to talk when such a long-lived world leader (even though she was mostly a figurehead) dies. It's natural to want to look back and contemplate, and even just reminisce, about how the world has changed under her. A discussion can be interesting without being a debate.

My rule of thumb is find a balance between "getting to the point" and accuracy. A study by itself in a specialized field will only be intelligible by a select group, but a science-based news site that can condense it appropriately is my goto.

It's certainly a best practice that should absolutely be encouraged.

Keep in mind:

It can take practice to get good at it.

People who are handicapped, distracted, short of sleep etc may try to do so and simply not get it right.

If you don't have the time to try to do this, you can just not submit it rather than tossing click bait at HN.

Was expecting a number comparing the amount of mutation with a regular non-astronaut's genetic mutation. It's not there.

I don't get it, how is it that the simple question of "compared to what?" is just completely omitted and seemingly never even considered by so many authors? Do people just operate with plain dead end facts without context or curiosity about how normal is even characterized or distributed? Is the idea of a nominal case/measure/etc so foreign? I wonder what series of basic questions could be memorized that could be a tool for authors to ask themselves to elicit getting this information or at least stating that the answers are unknown.

If I were on a tenure review board, I would argue against treating Nature papers as peer reviewed publications. I keep seeing obvious “strong reject” clickbait from them, specifically.

This paper is a prime example.

Are you referring to the paper, or the summary of the paper which was linked to here?

The actual paper. It’s the top link in the body of the article.

I’m confused…did you read the Science paper itself? In their _first paragraph_ they reference baseline genetic variation, and age-related mutation versus the mutations seen in cancer survivors and—as it turns out—astronauts, in the second paragraph. Lots more details and caveats on the limitations of the data elsewhere in the paper.

You seem to be reacting to this article, which is a popular summary of the findings. I don’t even think it’s a misleading article—it conveys the qualitative conclusion (elevated rates of nonstandard mutations), and answers to the questions you posed are available in the full scientific study…

The article links to a Nature paper. Are you reading a different paper?

https://www.nature.com/articles/s42003-022-03777-z.pdf

This is the closest thing I can find to a reference to a control in the first two paragraphs. The figures also suggest they did not have a control, so the use of the phrase “elevated rates” is baseless:

> Considering baseline genetic and extrinsic variability, the development of tools that permit the assessment of individual genetic susceptibility would improve risk stratification and long-term clinical management.

If funded, that still wouldn’t be a reasonable control.

Maybe I’m missing a key sentence or something, but I’ve read the paper, and it seems to boil down to:

“Mutations are bad, and this expensive piece of equipment measures mutations, so we stuck expensive astronaut blood in it, and the gauge pointed to a non-zero number”.

Later:

> Variants (SNP/ InDel) generated with this method were compared with a normal dataset using Archer’s analysis pipeline to distinguish noise from a true call. The normal dataset was created with sequencing data from seven young, healthy individuals.

From the article:

> in this astronaut cohort (median age 44 years, range 37–67),

I'd like to see also a comparison with 7 normal persons with ~45 years old. How many mutations is the expected value for a ~45 years old person?

Archer's analysis pipeline isn't a well defined statistical test. It's a UI that browses results from the type of machine they used:

https://www.enzymatics.com/news/archer-analysis-pipeline-upd...

They filtered the results with various p-values < 0.01. Their supplementary data:

https://www.nature.com/articles/s42003-022-03777-z#Sec9

doesn't say how many samples the machine produced in the first place, but it does say the filter resulted in 35 hits. That tells us absolutely nothing about the rate of mutations in the astronauts vs the general population, or even if astronauts produce more novel mutations on average vs. the general population.

On top of that, they seem to have the data to answer these questions, but don't report it anywhere:

Do zero-mission astronauts also show a "true call" in Archer's analysis pipeline?

They ran multiple samples from the same astronauts (before and after missions). On average, does the same astronaut have more/more-novel mutations after each mission?

These would require additional experiments or data, but seem obvious to check:

Do they have unusually high or low numbers of mutations vs. the general population at the same age?

If so, grouping the general population sample, what other professions also show a "true call" according to the pipeline?

Would have been nice to see a comparison to alternates who were otherwise qualified but did not fly shuttles.

Seems weird, but if they had actually done that (much better) experiment (which has a moderate to high chance of detecting no meaningful difference) it's quite likely the result would not be "interesting" enough to be published in a major journal.

With identical twins, one of each pair gets to fly, the other stays on the ground. They could also look for time dilation effects ;)

I'm not following several different aspects of your comment here. First of all, the paper is in Nature, not Science. Second, the first and second paragraphs do contain some relevant words, but nothing quantitative - literally the only quantitative number (not nomenclature number) in the entire first 2 paragraphs is CHIP being defined as >2% of something. Furthermore the reference to baseline genetic variation you mention is verbatim as follows: "Considering baseline genetic and extrinsic variability, the development of tools that permit the assessment of individual genetic susceptibility would improve risk stratification and long-term clinical management."

And I would argue that the article (not paper) does _not_ convey the qualitative conclusion of elevated rates of nonstandard mutations, because it doesn't reference the baseline at all! It doesn't even present it as a comparison, like "We found MORE mutations in astronauts than would be expected of non-astronauts" - it literally just phrases it as "We found mutations in astronauts", which, considering that non-astronauts are exposed to radiation and get cancer + epigenetic mutations as well, doesn't differentiate it from the normal expected observation.

You’re eliding an entire body of research with “>2% of something.” That assertion is cited, and links to a full study.

This is an observational study, and you may be analyzing it as a designed one. There was no randomization, no large scale matched control group per se—that wasn’t the intention. The intention is to analyze a specific population, and compare it to the existing literature on prevalence of mutations. That’s how these things are done, you have to use the citations given to understand the broader context of a study. One study is not useful on its own.

Also, there’s this—they did hypothesis tests against a control group:

How am I eliding anything? My statement is that the only quantitative number in the first 2 paragraphs is the ">2%" figure.

I'm also not criticizing the study, I'm criticizing the article and your defense of it. If "you have to use the citations given to understand the broader context of the study" - then if the point of a pop sci article is to effectively communicate the salience of the paper to lay audience, then that broader context needs to be communicated too.

No reasonable person reads “found genetic mutations in every astronaut” to plausibly mean “found bog standard genetic mutations everyone’s got.” This is pop science communication—journalism—not the actual scientific study. The goal isn’t scientific precision, it’s democratizing technical work

Really? I think everybody in the entire world knows somebody who's died from cancer, and the more educated of those people know that cancer is caused by genetic mutations. Also the theory of evolution is based on random genetic mutations - a very popular theory. I think a reasonable person would therefore know that everybody gets random genetic mutations over time.

To put it concretely, if the chance of a random gene mutation is 10^-4 to 10^-6 per gene per generation, and there are 37 trillion cells in a human body, each cell containing about 20k genes, (all numbers from quick google searches) then the odds of having NO genetic mutations occur in your body in one day would be (forgive my back of the envelope math, assuming a generation is 20 years): (1 - 10^-6)**(37 trillion * 20000 / 365 / 20). My calculator can't keep enough precision to make this nonzero. i.e., everyone has genetic mutations constantly which makes the title of the article completely uninformative.

There are some tricks to reduce the number of important mutations.

Germinal cells reproduce very slowly, so the eggs and sperm have fewer mutations.

Also, cells inside the guts have some cascade method. The cells near the wall reproduce very seldom, but the intermediate cells reproduce faster, and the inner cells reproduce even faster. The inner cells that are reproducing fast die or get washed away, so the big number of possible mutations is removed. And the slow reproducing cells near the wall create more cells to replace the intermediate cells that replace the inner cells.

Cool, that makes sense but I'd never seen it framed this way. (I knew about the slow rate for germ cells, but not gut.).

The article itself is full of caveats and concludes that their finding is inconclusive... Just some examples:

>Overall, further longitudinal studies are required to characterize CH and somatic mutational profiles in the context of space flight-associated stressors and their associated clinical impact. To date, there is no evidence of relevant CVD, cancer, or neurodegenerative diagnoses associated with this given astronaut cohort (current median age 62.5 years (IQR 60–67)). The lack of longitudinal samples from these same astronauts limits the assessment of clone stability, pathogenic potential, and prognostic value

But that the value of their report is in demonstrating the possibility of using stored archival blood samples in future studies:

>Thus, this study serves to address the feasibility of using bio-banked astronaut samples and demonstrate the importance of collaborations between NASA’s Human Research Program, Translational Research Institute for Space Health, Space Biology Program, NASA’s clinical support teams and corre- sponding data and biorepository branches,

Unfortunately, though, people far and wide are inevitably going to use this paper as evidence that space travel causes leukemia...

> The article itself is full of caveats and concludes that their finding is inconclusive... Just some example

It's a bad example. Mutations are known to cause various health problems like cancer. It's like randomly writing to the RAM, live: maybe you won't crash the computer immediately, but keep trying and you'll do damages.

The fact there's "no evidence of relevant CVD, cancer, or neurodegenerative diagnoses associated with this given astronaut cohort" shouldn't be surprising, given that astronauts are finely selected for perfect health among a large pool of candidate.

It's like saying "it's totally ok to do drugs or performance enhancer when you're a sports professional player" - no, they will eventually degrade the pro player health too!

Compared to a random person, it might just show later, as they have more of a health capital.

> Unfortunately, though, people far and wide are inevitably going to use this paper as evidence that space travel causes leukemia...

Given everything we know, yes it should, among other things - just like writing to RAM should eventually crash a computer

Mutations acquired during a lifetime are far more common that commonly believed; it's a key aspect of ageing. The astronauts in this study had an average age of 44, by which time they would be expected to have acquired mutations under normal, earthbound, conditions.

To address this, the study compares the number of mutations found in the astronauts with the number found in a broader population with mean age of 58 yrs. Notably, they do not conclude that more mutations were found in the astronauts.

That information is relatively well known to those familiar with the field of clonal hematopoiesis, and was likely omitted for brevity. It is not reasonable to expect lay public level of background information to be included in every discipline's scientific publications.

I'll point you to the two seminal papers in the field of CH though if you are interested. These were published back-to-back in the same issue of NEJM in 2014 (interestingly from separate competing groups at Harvard).

https://www.nejm.org/doi/full/10.1056/nejmoa1408617 https://www.nejm.org/doi/full/10.1056/nejmoa1409405

The actual study can be read at https://www.nature.com/articles/s42003-022-03777-z.pdf.

Methodology is given towards the end of the paper. In particular: "Variants [...] were compared with a normal dataset [...] created with sequencing data from seven young, healthy individuals."

They should have taken samples of the same age. Mutations accumulate over the entire life of the organism.

The full experiment, using old samples that degrade also, looks badly designed to point to a predefined desired answer. It somehow ended in Nature, probably because "authority appeal"

20+ year old DNA samples, even stored deeply frozen, could accumulate damage that would be amplified during library prep prior to sequencing. To make the case, they would really need appropriate control samples from the same time periods stored under the same conditions.

It's also worth noting that the samples they used were from a totally different age bracket than the astronauts.

Astronauts (aged 37–67) compared to "seven young, healthy individuals."

Setting aside the question of "compared to what?" (I presume they mean "more than normal folk"), I think it's more fun to brainstorm the question of "what could be done to prevent this?"

I'm guessing that the mutation danger is because space is just full of radiation that various layers around the earth give us partial protection from. So what can be done in a hypothetical spacecraft to get the same level of protection?

If we want to send people to Mars, or live in large numbers in space, these are fundamental problems to solve.

Of the proposed solutions, this one is my favorite:

https://en.wikipedia.org/wiki/Radiotrophic_fungus

I'd like to think that in this universe the best spacecraft asymptotically approach being a mushroom

Oh that is a delightful idea.

Now if we could breed them to also somehow produce usable fuel as a means of energy storage...

Maybe this is the beginning of living ships like in Farscape.

From the linked Nature article, my layman's interpretation is it seems a more severe finding (CHIP) was not found (and was possibly what they were looking for as CHIP may have indicated a potentially more material impact), and that this is more like an early, thin data set which can't be fully evaluated without more data:

>We identified 34 nonsynonymous SNVs in 17 known CHdriver genes, of which TP53 and DNMT3A were the most frequent. Notably, clone size was small, ranging from 0.10% to 0.95% VAF, and thus did not achieve the technical threshold to be considered as CHIP

and

>Due to the lack of longitudinal samples and small sample size, conclusions regarding the implications of observed lesions remain limited, and further studies are required to assess the penetrance of these clones.

Is that how the rest of you read this, especially those of you who are more expert?

I agree; that is basically my take, with two slight amendments:

I didn’t have the sense there was a value judgement (more/less severe), so much as that CHIP is “typical” mutation seen in the wider population, associated with aging (itself a fascinating field of research), whereas something novel / nonstandard is causing CH mutations (space?? That’s the implication).

On sample size, I read it as “this is interesting preliminary work that is surprisingly robust for the sample we have, and thus intrinsically notable.” But the passage you cite and the surrounding discussion indicates that this is far from conclusive—it’s a promising / interesting direction for more research to find out what’s the “there” there, if anything.

These things _could_ be coincidental, but such a high rate of consistency is strong signal to investigate further. This paper propagates that surprising result, which is also a unique analysis because of the lack of data the authors acknowledge. Without publishing this, others would have no access to even this preliminary finding.

NASA astronauts Mark and Scott Kelly are identical twins and scientists took the opportunity to do extensive tests with them. One pair of twins is not conclusive but the study is interesting.

The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight https://www.science.org/doi/10.1126/science.aau8650

NASA Twins Study Confirms Preliminary Findings https://www.nasa.gov/feature/nasa-twins-study-confirms-preli...

And the control group?

And how can we rule out that the mutations are not introduced in time at rest? All these blood samples are more than 20 years old.

Maybe the scientists manufactured the data with CRISPR. /s

In seriousness, we can come up with lots of out-there scenarios. But this finding is intrinsically interesting enough to warrant discussion, critique, and further analysis.

Your critiques aren’t a failure of the system, or a “dunk” on the scientific establishment. This open, democratic dialogue is _the entire point of the scientific publication process._

I am actually not critical of the deductions.I never even considered bad intentions.

Being skeptical is required to get to reality. Do we really know if the storage procedures/ thawing procedures can't have a side effect of mutations on the samples? We are still learning too much about the epigenetics and we already know low temperatures can have adverse effects on tissues. So I just voiced my idea on this.

Mutations are caused by errors in DNA repair mechanisms. Radioactive particles smash into DNA, breaking the bonds that hold it together. You have a whole system for DNA repair in your cells, but it's not 100% accurate, and so the more times you have to repair things, the more errors you're going to see.

And the reason you'll never see it in random frozen samples from 20 years ago is that your cells have to be alive for it to happen, and those ones aren't.

Well you are right when you consider that a "mutation" can just be caused by the DNA copy/repair mechanisms. But what if a chemical degradation could also cause it? Perhaps a sample dna lost bases and the sequencing read the resulting base sequence as a new mutated sequence? I am just being skeptical.

The samples were stored at -80°C, where any chemical degradation process would be slowed down immensely if not come to a virtual halt.

Thing is, if your freze something, that does not stop its internal decay due to radiation, e.g. carbon 14, kalcium etc, its just that the errors which occur arent multipled and the relatively short time is insufficient. But freeze a corpse for a millenia and it will turn into swiss cheese from self radiation, even if it was healthy when you froze it.

+10 if I could. Especially since the article notes that such mutations can be caused by "exposure to excess ultraviolet radiation". AKA sunburn?

I mean, yes, sunburn is excess ultraviolet radiation, but there are lots of other (more severe) forms and it’s pretty straightforward to understand they mean “excess [beyond the type experienced in the comparison populations, namely, the general population, who tend to experience minor exposure to excessive ultraviolet radiation, aka sunburn].”

This isn’t the “gotcha” you think it is.

There is a difference in where the mutations occur in the body. Sunburn still primarily causes mutation in and near the skin. radiation can cause mutations in the organs deeper in the body which are less robust against radiation, for the exact reason that the skin is usually a sufficient barrier.

See the twin study, as mentioned by someone else.

Does anyone know if astronaut living quarters are designed to have equipment, water etc. placed in a way to maximize shielding? I.e a water tank that is shaped like a shell rather than a tank.

While I don't know the answer, I'd think maintainability is the big constraint there. In the extreme case, imagine the difficulty of pinpointing and fixing any problem when all your systems are nested shells with a massive surface area. You'd need to take half the station apart any time something went wrong.

Question: in space, is the direction where radiation comes from distributed evenly, is all radiation coming from one direction, or something else?

> in space, is the direction where radiation comes from distributed evenly, is all radiation coming from one direction, or something else?

Mostly directionally from the Sun. Reflected radiation comes from the reflection surface. Cosmic background from dark sky (which isn’t all directions if you’re near a blocking body).

That said, the point of these studies is to measure how much damage which kinds of radiation cause. So short answer, we’re not sure. (But probably the Sun.)

Ok.

Now I'm wondering, if you go from the space ship, say 1000 km into the direction of the Sun, and then somehow apply a very small force to the radiation, would it be possible to make the radiation go past the space ship?

> then somehow apply a very small force to the radiation, would it be possible to make the radiation go past the space ship

For charged particles, yes. This is how the earth’s magnetic field [1] protects us.

[1] https://en.m.wikipedia.org/wiki/Earth%27s_magnetic_field#Mag...

A combination of directed and distributed evenly. There are 3 (sort of 4) sources of radiation.

1. Trapped protons and neutrons in the Van Allen radiation belts. The ISS is well below the first Van Allen belt but it is really a continuous spectrum with peaks and valleys. For example there is the South Atlantic Anomaly where the inner radiation belt dips lower and flying through this region exposes you to more radiation. This is the fairly distributed radiation source

2. The sun. Solar storms, coronal mass ejections, all of these increase radiation. Although these may not be facing the sun as much as you might think. The radiation bends around the magnetic field of the earth so this often affects things closer to the poles of the Earth (and causes the Auroras) and spacecraft in high inclination orbits.

3. Galactic Cosmic Rays (GCRs). These are from far off events like supernovae or black holes but are really high energy. So direction is generally "from the galactic disk" but that is a pretty wide direction

4. Bremsstrahlung. This is basically radiation caused when one charged particle deflecting/slowing down another particle. The interaction causes some radiation (usually in the form of X-rays, or gamma rays if you get something coming in real hot) but basically comes out as the vector component of how the particle was deflected so it can be from a number of directions. https://en.wikipedia.org/wiki/Bremsstrahlung#In_astrophysics

That’s the plan for trips to Mars. Water storage would be in a void between outer walls, creating a somewhat / partially protective barrier.

Layman question: Did gravity took any part on life creation on Earth? Do we even know if life or DNA can even form in non or low gravitational environment?

it's pretty certain that life in this form would not have formed without gravity though.

I think the closest to a 'low gravity' environment is the oceans. So I suspect yes, life would form in low gravity environments. It would likely have more rotational symmetry vs mirror symmetry land animals have. You see a hint of that in ocean life where things are more...round.

Most sealife has mirror symmetry though, doesn't it?

I guess jellyfish, urchins meet the rotational symmetry though.

That’s about aerodynamics (hydrodynamics?), as water is more resistive than air.

Now you've got me wondering - what is the difference between buoyancy and low gravity (with respect to organism development/evolution)? Would there be any meaningful differences structurally?

I would think yes. In a submarine, the vessel is buoyant, yet the contents are subject to regular gravity. I think the same reasoning applies to a body and its organs and fluids. Contrast with space where everything floats.

> I think the closest to a 'low gravity' environment is the oceans.

The oceans are not a low gravity environment, and gravity is no less when floating in water. Depending on the density of the water and the object that is floating, it is buoyancy that causes floating in water. Gravity works the same on the floater and the water.

And we could correctly assume gravity is essential for life, as without gravity, not even the Earth would not revolve around the Sun, let alone whatever it is that life is supposed to form on in low gravity, and we know that light is essential for life.

It's still an open question how life formed from non-life(look up abiogenesis).

It's also an open question whether it formed on Earth at all or came here from elsewhere.

So there is no answer to your question as yet. Or at least there's no scientific consensus on one.

We know DNA and and even semi self replicating biochem molecules can form both in the presence and absence of gravity. It requires a suitable energy gradient though, and I like the idea that cyclical changes in the energy gradient are required for evolution to occur rather than stagnating in a specific state. This is partly why tidepools are an interesting candidate for early life.

The fantastic four were right after all. Space radiation is no joke.

Joke aside, even for regular flight crews and passengers, it is a subject of concerns [1].

[1] https://pubmed.ncbi.nlm.nih.gov/11603132/

The idea of how they recycle drinking water is also of high concern to me personally... What if the equipment breaks or underperforms?

People constantly act as if science and technology is flawless in execution, but in reality it rarely is.

There is also space radiation and other factors that can easily affect bio organisms, without any way of knowing what happened here on earth. COmpared to the ideals of Star Trek, we are still vastly primitive in terms of understanding space... Makes me kinda sad how much safety needs to be risked just to explore the outer bounds.

You're putting the cart before the horse. Exploration is cool BECAUSE it's risky. If it were a walk in the park it would just be data entry.

From the paper,

> We obtained de-identified whole blood samples from 14 astronauts who flew relatively short Space Shuttle missions (median 12 days) between 1998–2001. These samples were stored at −80°C for ~20 years. Blood samples were collected 10 days before flight, the day of landing, and 3 days after landing12. However, for this specific study, only samples from 3 days after landing (R + 3) were collected as buffy coats (peripheral blood mononuclear cells - PBMCs).

One of the issues here is of the biased sample set. To say that astronauts are drawn from a small pool is a severe understatement. All astronauts from the stated era have,

    - High IQs
    - Absence of obvious psychopathologies
    - Extremely high stress tolerance
    - Faster (than the median) reaction times well into middle age
    - Usually within 3SD for M/F height, falling between 5' to 6'2 (6'4 at most)
    - High educational attainment

And they've all done,

    - Scuba diving (sometimes including extended stays as aquanauts)
    - Pilot training (even if you're a scientist astronaut, they'll teach you how to fly, [edit - as Walter points out flight hours equal radiation exposure and NASA astronauts usually have to maintain a minimum of 180 hours per year to retain their flight status])
    - *At least* one sport where they've risked their life
    - Undergone wilderness survival training, including a "hell week" of some sort, somewhere along the line
    - Experienced near drowning (part of training) and other similar stressors
    - (frequently but not always) Been a part of the military, including exposure to pollutants that we now know are carcinogenic or harmful.

Additionally, during this period, unless they were an international astronaut,

    - They would eat similar foods, from the same places
    - Live in close proximity to each other
    - Grow up in roughly similar environments (though split between urban/rural environments)

Of course, not all of these factors will impact their DNA, but the selection and similar life experiences creates a unique problem. Until we send more people up, we won't have enough data to say how space travel impacts and mutates us.

People who fly a lot get significant cosmic radiation exposure.

Thank you very much. This is what I was thinking, more or less, and didn't know how to effectively articulate.

As a comparison, I wonder if marine life under even just a few feet of water for their whole lives benefit from that added cosmic ray protection. Yet we don't see fish that live for hundreds of years just because of that, do we?

Interesting point. It's not conclusive, but if you do a quick search for the longest living animal species, the vast majority of them do live (all or part of their life) in water. So maybe?

Depending on the actual scope of the study (how many they sampled), even if samples were anonymously labeled, publication is a bound to be a violation of the Federal Privacy Rule protecting astronauts' right to medical privacy.

Human beings are earthbound creatures and can live in space only with the mother ship earth... which we are working on destroying.

Something might survive and thrive in space of course if it were properly designed for that.

I for one welcome our mutant astronaut overlords.

The obvious question is: How is this different from non-astronauts being affected by mutagens like chemicals and radiation? Are there any statistical differences?

I should hope that the general plasticity of an organism would kick in when the environment so fundamentally shifts

Sending humans into space is an expensive boondoggle that distracts and detracts from legitimate scientific research.

Whether or not outer space scrambles your genes, we know for sure that we've scrambled several astronauts and nearly scrambled several more.

I politely but firmly ask that we stop scrambling people to appease people who misplace their sense of wonder. Even if they volunteer to be scrambled.

Technically, so did I.

>The samples were then cryogenically stored at -112 degrees Fahrenheit for around two decades.

So "scientists" stored DNA for 20 years and then decided to take a closer look? Better than nothing, but not by much.

DNA sequencing wasn’t an economically feasible option 20 years ago

OK 20 years maybe it wasn't worth the cost, but by 2011 it was only thousands of dollars.

https://www.genome.gov/about-genomics/fact-sheets/DNA-Sequen...

https://en.wikipedia.org/wiki/DNA_sequencer#Comparison

Well you’re not addressing the GPs concerns. The DNA could be severely damaged.

If they did analysis using tools and methods that weren't available / affordable 20 years ago, then preserving the samples for that long might have been wise.

Ouch, it is not uncommon to freeze samples for a long time, especially rare ones like this. You're free to peruse the literature on how this is an accepted practice.

So I did. Searched and read about it, found out the viability and recovery of cryopreserved PBMC has a clear downward slope. Samples are good for years, not decades.

This depends on what you want to do. The DNA can certainly be sequenced. They might even be viable if you’re nice to them.

What I mean to say is this is an accepted practice in many labs, including ones I have worked in. In my experience, these were old tumor cells stored in LN2. Sources include: https://link.springer.com/article/10.1007/BF01131376

https://pubmed.ncbi.nlm.nih.gov/9336042/

https://pubmed.ncbi.nlm.nih.gov/27792414/

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