23andMe's DNA testing was always fun. Now it is more useful as well.

As anyone who follows this blog knows, I had my DNA tested awhile back by a company called 23andMe.  I wrote about what I learned and didn’t learn from their testing in a bunch of blog entries.

In my mind 23andMe has always been a sort of recreational genetics testing company.  You can find out about your earwax, whether you are likely to have blue eyes or be lactose intolerant and lots of other minor sorts of traits.  This is stuff you probably already know but for geeks it is pretty cool to see them written out in their DNA.

The company always offered some health data too but it wasn’t that strong.  For example, they could tell you if you carried the most common DNA difference that could lead to cystic fibrosis (CF) but not about the less common ones.  In fact, I gave them an incomplete for their carrier testing a few months back.

Since then, the company has gone away from being a place where you get your DNA tested for coolness’ sake to one with a focus on health and/or ancestry.  With this change has come a much-improved product for people interested in what their DNA tells them about their carrier status for a variety of genetic diseases.

Carrier status is important if you are considering having a child.  If you and your partner both carry the broken versions of a gene that could lead to a disease, then your child would be at an increased risk for getting that disease.  For example, if both you and your partner have a nonworking copy of the CFTR gene, then, depending on the exact DNA you each have, your child could have up to a 25% chance of ending up with CF.

This is why the first iteration of 23andMe carrier testing wasn’t as useful as I would have liked.  They tested only one of the 100’s of different DNA variants in the CFTR gene that can lead to CF. Since this DNA variant only accounts for about half the cases of CF, there was a good chance that something would get missed.  This is no longer true.

As part of the refocusing, 23andMe looks for 31 different variants in the CFTR gene that are known to cause CF. Now this isn’t hundreds but is more than the 23 recommended by the American College of Medical Genetics.  And in fact 23andMe includes these 23 in the 31 it tests.

Of course the testing still isn’t perfect but no testing is.  Some of the tests are only useful for certain ethnic groups.  And there is no upfront genetic counseling to help you decide whether or not genetic testing would be useful in your situation anyway.

But the bottom line is that 23andMe’s testing for genetic diseases that you might be carrying is much stronger than it was before.  So much so that it can even give you some piece of mind for many of these diseases.

In some ways I’ll miss the more whimsical look at DNA that 23andMe used to represent.  But this obviously wasn’t a good business model for anyone except those enamored of DNA.  And 23andMe does need to make a profit…

Missing two chromosomes but doing fine. A partial karyotype of a man with 44 chromosomes.

A doctor from China contacted me through this blog with some exciting news. He had found a patient with 44 chromosomes instead of the usual 46. And the patient was perfectly normal as far as anyone could tell.

The doctor contacted me because the story of how this patient ended up with 44 chromosomes mirrored my story of how humans may have gone from 48 to 46 chromosomes a million or so years ago. The idea that human chromosome reduction could happen this way was theoretical when I wrote about it. Now we have living proof that it can and does happen.

Sticking Two Chromosomes Together

At first it might seem weird that losing a couple of chromosomes had no real effect on the patient since losing even one is usually fatal. But his case is different because he didn’t really lose two chromosomes (and all of their essential genes). Instead the chromosomes ended up stuck to two other chromosomes. So he has the same genes…they are just packaged differently.

When this happens with a single chromosome, it is called a balanced translocation. These are more common that you might think with about 1 in 1000 people having one.

The way to end up with 44 chromosomes like our patient requires that both parents have the same balanced translocation. The only way this is at all probable is if the parents are closely related. In this case, they are cousins.

I won’t go into the details (click here to learn more) but these parents had a 1 in 36 chance of having a child with a double balanced translocation. And this is our patient.

From 48 to 46 to 44?

As I said before, a big reason why this is all so interesting is because it provides confirmation of one way that humans may have gone from 48 to 46 chromosomes so many years ago. The first step might have been similar to what happened to our patient. Two closely related parents with the same translocation have a child together that has fewer chromosomes.

Back then, chromosomes 12 and 13 fused together to create what we now call human chromosome 2. The fused chromosome then slowly spread through the community. And then, for some reason, the group of humans with 46 chromosomes eventually supplanted the group with 48.

We can’t know for sure, but this may have happened through some random event where the 48 chromosome humans were mostly wiped out and the humans with 46 chromosomes were spared.  Humanity has nearly been wiped our before with the most recent case being a volcanic eruption 75,000 years ago.

If something similar happens in the future, I wonder if people will be questioning our close relationship to chimpanzees. “How could chimpanzees be our closest relatives,” these future folks might ask, “when we have four fewer chromosomes than they do?”  This assumes, of course, that the number of chromosomes has not changed in chimpanzees by then…

Too fancy for some California schools.

As part of an HHMI-funded initiative, I do some outreach to a high school in a poorer part of San Jose. Basically a bunch of us run some hands on genetics experiments to try to get the kids to see how fun science really is. Hopefully this will get a few excited enough to want to learn more on their own and maybe one or two will even want to become scientists themselves.

Going to this high school has been an eye-opening experience. You don’t really appreciate how much California (and by extension Californians) have given up on equal education until you spend some time in a poorer district.

Most voters probably don’t have a sense of how resource-starved these schools can be. Yes, we hear all the time about the cuts in the education budget and the adverse effects they are having on schools. And the school districts where most of us live have gone a bit downhill in the last few years but most of us are satisfied enough with our schools. If we’re not, we send our kids off to private schools where, in the eighth grade, they can test whether foods are genetically modified or not (I kid you not).

But to understand how bad it really is, visit one of the nearby poorer schools. For example, last semester, the school I go to ran out of paper and had no money to buy more. No, really…they had no paper.

Kids were taking tests on left over Post-It notes (because there seemed to be some of these still around). And they weren’t getting worksheets or anything else like that. I have to say I was stunned when I heard this and so is everyone I tell this story to. Where do we live, Bangladesh? Malawi?

This becomes even more upsetting when you consider where we are. The valley has taken a hit from the recession but plenty of people still send their kids to schools in Los Altos, Palo Alto, Hillsborough etc. There still seems to be a lot of money rolling around in the system.

Luckily a bit of the money rolled over to the school that ran out of paper. After a week the school district found additional funds to keep buying paper. So the kids only had to endure this for a single week but I am sure they will never forget what happened.

And I worry even more about next year. Everything I have heard is that there will be additional cuts to the education budget next year. Are they going to shut off the power next? Or maybe they’ll just give the kids sticks so they can take their tests on the ground in the courtyard.

Unfortunately I have no idea what to do about this. I would think more money would be good but that’s not going to happen. Any ideas?

Carl Sagan’s scientific career took a bruising because of his outreach work.

I am convinced that a lot of people’s misconceptions about science could be cleared up with a little outreach from scientists. I’m talking about outreach activities like creating websites that give good, reliable, understandable information, talking to school and adult groups, getting involved in museums, PBS, the Discovery Channel, etc.

Getting scientists to do any of this is the tricky part. They have no immediate incentives to do it and in fact, there are disincentives. But they need to learn that it is in their best interests.

Taxpayers pay most scientists’ salaries through federal grants. An uninformed, suspicious, or actively hostile public obviously will not want to pay for scientific research. So anything that can be done to inform the public about the good work being done will probably loosen the purse strings in Washington at least a bit.

Of course the problem with this argument is that it uses an abstract fear of something in the distant future. Sort of like global warming.

As we’ve learned from that, most people aren’t willing to sacrifice much for far off, future dangers. If gas is cheap, we’ll keep driving big cars. And we certainly won’t sacrifice any current goods for a future that may or may not come to pass.

Same thing with scientists. Outreach is a thankless task that can actually work against the people who do it. Scientists who do a lot of outreach are often perceived as not being serious about true science and they’re dinged for it.

There is also no incentive at Universities to do outreach. As anyone who has been involved in academic science knows, the key to success is to get government grants that help fund the scientist’s research, his or her department and the University. Everything else an academic scientist does takes a backseat to this. And outreach isn’t even in the car.

Outreach takes scientists away from the lab. It is in the lab where results are generated that can be published to get grants to fund more research. Less time on research equals less money.

So to get scientists doing outreach, we need to change the incentives. There either has to be a change at Universities so that outreach is valued. And by valued I mean tenure track positions or long term funding for people to do outreach. Frankly this is pretty unlikely.

The other possibility is to include outreach as part of a scientist’s grant. In other words, to get money for their research, scientists will need to do some outreach.

I am aware of two major funding agencies—the National Science Foundation (NSF) and the National Human Genome Research Institute (NHGRI)*—that mandate outreach for at least some of their grants. These mandates are a critical first step in getting more digestible science out to the public. But to make a major dent, we need the NIH to get involved too. They fund a whole lot more research and so a whole lot more outreach would get done too.

The NSF and NHGRI requirements are definitely causing a lot of scientists to scramble around and try to find outreach projects to fund. (Email me if you have some spare money lying around!) But I don’t know the quality of the outreach that is being done.

Hopefully the people doing outreach are better than the average scientist at talking or writing about science with the public. For the most part, the money would probably best be spent on hiring someone with a scientific background who is good at explaining science. Or in training scientists first in how to effectively communicate science to the public.

All of this points to another major issue—we need to figure out what we want from these outreach opportunities. Is it to provide a good source of information for the public? To enhance understanding of how science works? To teach people how to tell good science from bad? To train the next generation of scientists? To…? No one is really providing leadership on these questions. Let’s hope someone does soon.

*The NHGRI is interested in increasing the numbers of genomic scientists who are under-represented minorities. Definitely worthwhile but not really doing a lot for the public understanding of science.

Here is a great book on the subject: Unscientific America: How Scientific Illiteracy Threatens our Future.

It can be hard to tell which science is good, bad, or ugly on the web.

I have often thought that the percentage of good scientific information on the web must be pretty low. So I decided to test the idea out on a question I was recently working on.

Someone asked me if humans started out with O blood type and then only later developed A and B.  A quick look at PubMed showed that this was not the case.  Most of the recent genetics studies point to A coming first, followed by B about 3.5 million years ago and then, finally, about 1 million years ago, O.

This makes some intuitive sense if we think about what A, B, and O are.  O is a form of A that doesn’t work any more because of a mutation*.  This makes the idea that a broken gene came before a working one pretty unlikely.  Not impossible, just not all that likely.

Now I researched this answer the way I usually do—I headed straight for PubMed to get the hard scientific data.  I can do that because I work for Stanford and so have access to lots of journal articles and I have the scientific background to decipher the geneticsese these reports are written in.

What I also did this time was to try to find the answer without PubMed.  I started out on Yahoo searching for human blood type evolution.  Yikes.

Links 1, 2, and 7 talk about primate A and B blood types.  Gorillas have B and chimpanzees have A and a bit of O.  From this the authors try to conclude that we are somehow a mix of these two…perhaps gorillas and Neanderthals are closely related to each other and so are chimps and Cro Magnon.  In this scenario, humans come from a mix of Cro Magnon and Neanderthals.

This is certainly not the case.  Gorillas do have a blood type similar to B but it isn’t the same as ours at the gene level.  And if current evolutionary history is to be believed, we split from gorillas way before our B blood type was born.  So we did not get our B from gorillas.

Also, chimpanzee O is not the same as our O…it developed well after we split as well.  We even know that Neanderthals have our O blood type and not a chimp’s (and certainly not a gorilla’s!).

Links 3, 5, and 9 use blood type genetics to show that Adam and Eve could have founded the human race.  Links 4, 6, and 8 talk about the blood type diet.  And link 10 connects blood groups to aliens.

Google does a bit better.  You get eight similar links but you also get an NPR piece that does pretty well and a Dawkins forum comments piece that can get you to the answer eventually.  However, you have to wade through a lot of stuff to get there and you only know to home in on the comment with the correct information if you already know the right answer.

Obviously what is popular isn’t always what is right.  (And the prize for stating the obvious goes to Dr. Starr!)  I thought I’d try Wikipedia next.  Wikipedia can have many factual errors but it often gets the overall story line correct.  Unfortunately there isn’t an article on this subject.  There is on one the blood type diet though…

So what is a non-scientist to do?  There don’t seem to be a lot of options.

There are websites like mine at Understanding Genetics that try to give the real scoop on what current science says about various issues.  But they tend to focus on a single topic and don’t often appear at the top of a website search.  (Understanding Genetics is an exception in that it gets enough hits to often be on the first or second page if the query is worded in the right way.)

I am not sure what the answer is to getting better science via the web.  Maybe we need a web based encyclopedia about science written by scientists.

The tricky part will be to get them to do it.  And to have it make sense to anyone but another scientist in that particular field.  And for them to do it impartially.

I’m curious how other people find their science online.  And how they make sure it is reliable.

* This isn’t weird, blue eyes and red hair work the same way.

When choosing an embryo, a little bit of knowledge is a dangerous thing.

People often think about certain versions of a gene as either good or bad. One that leads to depression is bad while one that protects you from HIV infection is good.

For most genes this is almost certainly too simplistic a view. Many versions of genes can be good or bad depending on your situation.

For example, the delta 32 version of the CCR5 gene can make you more resistant to HIV infection. But it also makes you more susceptible to infection by the West Nile Virus.

Which version is best for you depends on where and how you live. If you’re an IV drug user who lives somewhere up north, then you would probably benefit most from the delta 32 version. But if you are a faithfully monogamous man in Africa or Central America, then you might do better with the more common version of the CCR5 gene.

As I talk about in a recent GeneWatch article, the same is true for the SERT gene and depression. This gene comes in two versions, long and short.

Studies have shown that people who only have the short version are at a higher risk for depression. A deeper look at the data shows that this is only the case if these people had a traumatic childhood. People with two short versions who had a happy childhood are actually more resistant to depression than people with the longer gene versions.

This all matters because we are at the point where you can choose some of your child’s gene versions. And too simplistic a view of genes could cause you to make the wrong choice.

People who undergo in vitro fertilization (IVF) can go through an additional procedure called preimplantation genetic diagnosis (PGD). Basically PGD allows you to look at an embryo’s DNA before it is placed in the womb. This means that when multiple embryos are created, you can choose which one to implant based on its genes.

Fortunately we can’t really change the embryo’s DNA for the foreseeable future so you’re stuck with whatever genes you and your partner can contribute. But as we are able to look at more and more genes with less and less DNA, we are getting very close to a Gattaca-like future where we can choose many of our children’s genes.

And as the two previous examples showed, this won’t be a simple choice! There are undoubtedly hundreds of genes just like these where what effect they have on someone depends on how and where that person lives, how they were raised, etc. It might be best to restrict this sort of thing except for cases where the child might end up with a devastating illness like cystic fibrosis or sickle cell anemia.

In some ways, this sort of thing is already being restricted. For example, when a fertility doctor in L.A. suggested that he might offer parents a chance to choose what eye, hair, and skin color their children might have, the public uproar shut down the service before it even began.

I’m not sure that less politically sensitive gene selection would cause such a furor. It may be that we need some sort of government regulation to protect people from what they don’t know. Or maybe parents need to take a course before selecting which embryo they want…

For most of us, avoiding these is just as important as the genes we inherit.

As someone who studies genes, I tend to give the environment short shrift. I have to watch out for that because it can cause a blind spot in how I think about biology. And how I live my life.

As readers of this blog might remember, I was recently diagnosed with metabolic syndrome just as I was undergoing DNA testing. This was a wake up call in a couple of different ways.

First off, it confirmed my belief that we can’t get a lot out of genetic testing for complicated diseases right now. I couldn’t look at my DNA and predict that I would end up with high cholesterol, triglycerides and glucose levels. We just don’t know enough yet about our genes to be able to figure this out from any available DNA test.

But I could have guessed this might be a problem from my lifestyle and family history. All four of my grandparents developed Type 2 diabetes which put me at a pretty high risk. Of course I thought I could beat the odds and so lived a life filled with couch sitting, Haagen Dazs, and Double Western Bacon Cheeseburgers (cue Homer Simpson drool). Until my diagnosis.

Then I decided to see if all this talk of diet and exercise actually can have a significant impact on me. Or was I destined to high cholesterol, triglycerides and glucose levels because of the genes I got from my parents.

The doctor told me to lose weight, exercise more and eat better. So I did.

I lost 30 pounds by changing my diet and walking 30 minutes a day. This dropped my body mass index (BMI) from overweight (27.8) to normal (23.5).

I also stopped eating most sweets, and cut my saturated fats down to 15 grams per day. And the effects on my blood work have been amazing.

Here are a few of the stats:

As you can see, everything is now in the normal range except for glucose which is still a bit worrisome. Now I just need to maintain this regimen which, in America, won’t be easy.

I probably panicked and went overboard anyway. I should have tried to just add exercise and see if that was good enough. If not, then cut back on sweets and saturated fats. I did bad science on myself by changing too many variables at once.

I think what I can conclude is that my set of genes makes me particularly susceptible to my lifestyle choices. Some lucky people are born with genes that let them get away with poor diet and no exercise.

I am not one of those lucky ones. Although perhaps more lucky than those people who make these changes and still have these health issues.

Current DNA tests could not have predicted that George W. Bush would be our 43rd President of the United States.

Time recently had a great article on helicopter parents. These are the parents who hover around their kids, protecting them from any harm. They are undoubtedly doing this to ensure their kids’ success in life.

I don’t want to get into the plusses and minuses of this parenting style…to each his own. What I do want to do is to warn them away from a new genetic testing company that seems designed to target them.

This testing company, called My Gene Profile, claims to be able to use genetics to help parents figure out where their child’s inborn talents lie. The idea, then, is for parents to point their children towards interests or careers that match up with what the genetic test says.

The talents the company is looking at are not simple ones like tongue rolling or bending your thumb back (neither of which we can yet determine genetically). They claim to be able to tell you if your child will be smart, creative, good at sports, and near as I can tell, five other similarly broad traits.

This is impossible given our current knowledge of genetics. And frankly, I am not sure we’ll ever be able to figure any of this out with a simple genetic test. Most of these traits are more than just the DNA we inherit.

Let’s take IQ as an example. Most of the studies I have seen point to about half of someone’s IQ coming from genes and the other half from the environment. Any test done right now won’t look at how the environment affected a child’s DNA. And they certainly won’t look at how the environment influenced the growth and development of the brain or how it affected synapse connections or about a million other things to do with intelligence and the brain.

Still, 50% from genes is a lot. If we could get a complete readout of how our genes influence our IQ that might be at the very least interesting. But we can’t.

Scientists believe there are at least 100 genes that contribute to IQ. So far they’ve only identified a handful and none of them have been shown to have reproducibly significant effects on IQ.

For example, scientists have found that having certain versions of the CHRM2 gene affects your ability to organize things in a logical way. The effects aren’t huge though. 23andMe (a company that I have tested with) reports that the variations that they look at in this gene can lead to a 6 point swing in IQ. Woopty doo.

If you drill down a bit farther, some scientists claim that you can get much larger differences. For example, at the furthest extremes, people with one set of variations in this gene averaged an IQ of 85 while people with a second set averaged an IQ of 103. Sounds impressive.

Except that a larger follow up study was not able to see the same effect. In this study, scientists weren’t able to find any connection between variations in the CHRM2 gene and IQ. And CHRM2 is by far the best characterized IQ gene.

Most likely the way that genetics contributes to IQ is that each of the 100 or so genes tweaks IQ a bit higher or lower. So to get a complete readout on IQ you’d need to look at all of these genes. This is difficult to do right now since we only know about a few of them.

And to make things even more complicated, the genetic contribution to IQ probably isn’t a simple summing up of these different variations. They don’t exist in a vacuum—these gene variations all interact with each other too.

What this means is that we may never be able to get an accurate prediction about genetic IQ from our genes. There are lots of possible combinations all with different outcomes. In other words, everyone’s IQ genetics may be unique which would make predictions impossible.

The bottom line is that there is not nearly enough data out there to figure out someone’s IQ or intellectual potential. And this goes for athletic ability, creativity and any other similarly complicated trait. We can’t even predict eye color yet very well from our DNA!

So consumers be aware of what a genetic test can and can’t deliver based on what scientists know. Testing for cystic fibrosis, pretty good. Testing for intelligence, not so much.

A final example. Imagine that Einstein’s parents had tested his genes for IQ with a company that looked at four or five IQ genes. And let’s say that he happened to have versions of these genes that lead to a lower IQ. Of course, since it is Einstein his other 95 or 96 or so IQ genes swamp out the effects of these few genes. But the testing company misses this and recommends that he not take an academic career. A little knowledge is a dangerous thing.

*This is common with genetic studies. There is a promising result with a small group that disappears when scientists look at a larger group.

If a DNA testing company gets bought out, what happens to their customers' DNA? Image by Molly Eyres. / CC BY 2.0

One niggling worry I had when I decided to get some genetic testing from 23andMe was what would happen to my DNA if the company failed. By all accounts, 23andMe is a very healthy company* so it was more of a theoretical worry for me. Not so for deCODEme folks…

Like 23andMe, deCODEme looks at hundreds of thousands of different areas of a customer’s DNA in order to predict that customer’s future health and provide information about his or her ancestry and traits. This week deCODEme’s parent company, DeCode Genetics, filed for bankruptcy. Press reports indicate that parts of the company will go up for auction. I am not sure if that includes deCODEme but I am sure all of their customers are sweating it out right now.

The big question now isn’t whether these people will still get good service from deCODEme. Instead it is what the company that buys deCODEme will do with all those customers’ DNA. Will they maintain deCODEme’s previous privacy policies? Or, in the worst case scenario, will they connect DNA to name and sell the combination to the highest bidder?

I have to say that at first I was a little panicky when I started thinking about this. Especially when I started to contemplate what my health insurance company would do to me if they got a hold of my DNA.

Everyone has some genetic problems lurking in their DNA and I am sure that insurance companies would be happy to limit or even drop people’s coverage based on this. The new health care reform bills are supposed to prevent an insurance company from dropping someone based on a pre-existing condition but I am not sure if something like this counts. If it doesn’t, then I would probably end up with a policy that doesn’t cover conditions my DNA says that I am more likely to get. (Very useful insurance!)

If the new bill does consider potential risks from our DNA a pre-existing condition, then this isn’t really that big a worry. Except that I bet the new bills allow the insurance companies to jack up someone’s premiums based on their pre-existing conditions. In which case they’ll charge me so much I’ll have to drop my coverage anyway.

The other possible uses for my DNA that I could think of paled in comparison to this one. For example, I don’t think I’d mind if they sold my DNA to a pharmaceutical company so that the company could make a useful drug. Or to academics so that my DNA could be used to learn something about the human genome. It seems like those are sort of noble purposes for my DNA, kind of like donating it to science.

I couldn’t really think of much else that other companies might do with my DNA. Of course if the health insurance scenario were to happen, that would be plenty bad enough.

* Especially since one of the cofounders, Anne Wojcicki, is married to Sergey Brin, Google cofounder.

"Mysteries of DNA" image courtesy Mark H. Adams. Full-size version.

As anyone who follows this blog knows, I recently took a 23andMe genetic test and have been blogging about it ever since. Today I thought I would focus on one of the fun parts of the service: traits.

Lots of our traits are at least partly dependent on our genes. So a genetic test should be able to tell me a bit about what I’ll look and even be like in the future. It may even tell me what I can expect for my kids.

Here is what is available on the 23andMe test (click on the image for a larger version):

As you can see, some of this is pretty obvious…I know my eye color for example. It is kind of cool to see my blue eyes written in my DNA but not necessarily that helpful. When I click on eye color, I find out that people with this particular bit of DNA have a 72% chance for blue eyes, a 27% chance for green and a 1% for brown. (Incidentally, this 1% brown is probably a big reason why blue-eyed parents can have a brown-eyed child.)

What would have made this report more interesting for me is what it meant for my kids’ eye color. Does it mean I’ll have blue-eyed kids? This of course depends on my wife’s genes but it would be cool to have the option of including my wife’s data to find out.

Other less obvious traits were very interesting to me. The results say that like most mammals, I should be lactose intolerant. Which I am not—I’m fine drinking milk. So did 23andMe get it wrong?

Probably not. The science is pretty good on this topic. People with a certain difference in their lactase gene almost always lose the ability to make lactase as adults. No lactase means lactose intolerance.

When I dug deeper on the website I got some hand waving about other genetic influences or the environment. A better explanation is that I will probably become lactose intolerant at some point in my adult life—it just hasn’t happened yet.

Losing the ability to make lactase is a gradual thing. It happens to some people early in adulthood and others later on. I am probably one of the “later ons.” Something to look forward to…

One trait that I’ve always been a bit interested in is HIV resistance. Some people are more resistant to infection by HIV (the virus that causes AIDS). If these people do become infected, they tend to develop AIDS symptoms much more slowly as well.

In Europeans at least, this resistance has been tied to a DNA difference called CCR5-delta32. The people who are resistant to infection and who develop AIDS more gradually tend to have two copies of this DNA difference.

This DNA difference has been proposed to have become common in Europeans because it also makes people resistant to either the plague or smallpox. If true, my ancestors must have died like flies from the plague or smallpox because I don’t have the DNA difference.

I also now know about what my DNA tells me about my earwax, how I respond to a certain bitter chemical, and whether I flush from alcohol. These are sort of interesting but not very.

This part of the 23andMe experience is kind of fun though. I really enjoy it when genetic theory matches up with what I can see about me. It sort of validates genetics…