Universal genetic testing may cause the break up of some families.

What became clear to me at a recent meeting I attended is that most everyone is going to have his or her DNA read in the near future. Another thing that became obvious is that scientists aren’t doing enough thinking about what impact this will have on society.

Here’s a seemingly trivial example. In most scenarios I have seen, children‘s DNA is read as soon as they are born. This will definitely have some huge health benefits especially as we learn more and more about how our DNA works and what it means. But this will also have some big unintended consequences too.

Parents will know both their kids’ and their own DNA. From that it will be pretty easy for most anyone to piece together whether or not a child is related to them. In other words, if everyone knows their family’s DNA, then every family will automatically undergo a paternity test. And if some statistics I have seen are true, then a whole lot of people are in for a nasty surprise.

The most recent numbers that I have seen are that something like 3-4% of fathers are unknowingly raising kids who are not their own*. Universal DNA testing will undoubtedly spill the beans in these cases causing many families to break apart.

This “misattributed paternity” is not an unknown problem today…genetic counselors deal with this sort of thing in their practice on occasion. Genetic counselors struggle with what to do with this collateral information and have the option of not revealing it to their patients. Withholding this information won’t be an option in a future where families know their DNA.

So in the not too distant future, up to one million dads in America will find out that little Susie or Jimmy isn’t theirs. Some will be able to deal with this but it will tear many families apart. This will obviously have a huge impact on society.

There will be more subtle effects too. Both men and women will quickly figure out that paternity won’t ever be a secret any more. If you have an affair and have a child, you will be found out.

Will this knowledge work as a sort of moral police, preventing people from having affairs? (Probably not.) Will people be more careful about contraception? Will abortions increase to cover up affairs?

As you can see, just knowing this little bit about our DNA will have profound effects on society. And I haven’t even talked about how medical care and the insurance industry might be restructured. Or how it will affect who you decide to have kids with. Or…

* This is the latest estimate I could find which is much less than the 10-30% number that med school students used to be taught. We won’t have an accurate number until more genetic testing of families is done.

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If you’re an adult and you can drink milk, then you are a mutant. Image courtesy of Collectie Willem van de Poll, via Nationaal Archief.

Over the last couple of weeks it has become obvious that my daughter is lactose intolerant. In most of the world, that wouldn't be a big deal. One study I saw claimed that at least 3 in 4 adults worldwide are lactose intolerant. And in some countries (like Thailand), over 99% of adults can’t drink milk as an adult.

This makes sense since lactose intolerance is the norm for mammals. Humans are one of the few animals where a sizable minority of adults are lactose tolerant. Scientists have noted this and have renamed the Eurocentric "lactose intolerance," lactase persistence.

Sigh, scientists never make things easy do they? Why not call it lactose tolerance so everyone understands?

They named it lactase persistence because of how lactose is digested in our bodies. Lactose is digested by the enzyme lactase and lactase persists longer in people that are lactose tolerant. Hence, lactase persistence.

Our cells make lactase by reading the lactase gene. In most mammals, this gene gets shut off in adulthood.

The programming for turning the gene off later in life is found in the DNA around the lactase gene. People with lactase persistence have a DNA change that messes with the programming. Now the lactase gene stays on so these folks can keep drinking milk and eating ice cream.

The “on” version is actually dominant over the normal one. In other words, lactose intolerant people need to get the normal lactase gene from both parents. So my wife and I are at least carriers—we can drink milk but carry one normal lactase gene.

I actually know that I am more than a carrier. I have two normal lactase genes even though I can still drink milk. This means that my gene hasn’t shut off yet but that it probably will at some point. Scientists don’t yet know why it shuts off early in some people like my daughter and later for others like me.

So how did some people end up able to drink milk as adults? Mutations and natural selection of course.

Most likely there is always a low level of lactase persistence in any mammalian population. Mutations (or new DNA changes) can and do happen and changes like this in the lactase gene are bound to be pretty neutral. In most situations there won’t be any advantage or disadvantage to having it and so it will stay rare.

This can all change if adults suddenly have to start drinking milk as happened in certain cultures in Europe and Africa. In these places, the few people with the right lactase mutation had an advantage and so did better than the lactose intolerant. Eventually, most people in these places could drink milk as an adult.

What is really interesting to me is the fact that European and African milk drinkers don’t share the same DNA difference. Each population had a distinct lactase mutation that became the norm. This is called convergent evolution—two populations arrive at a similar trait with different DNA changes.

However it happened, my daughter is now adjusting nicely to the milk-soaked culture she finds herself in. There are pills that let her drink milk as well as lactase-treated milk and ice cream. This means she can still have her favorite dessert in the world, chocolate ice cream.

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A few minor tweaks to genetic testing companies' websites could make their offerings more transparent to the public and the FDA.

The last couple of blogs I have been talking about direct to consumer (DTC) genetic tests. I talked about how the FDA has begun looking into them and why the FDA isn’t happy with what it sees.

In this blog I thought I'd propose a couple of different ways these DTC companies can present their data that might mollify the FDA. These changes will also let consumers know what they're really getting and whether they want it at all.

Before starting, I want to say that I will focus on 23andMe, a Bay Area company. I'm not picking on them. They are just the company I know best and one of the few that is good enough to survive the FDA's scrutiny. I also know a lot about them because I have taken their test.

23andMe has a very good website. They present complicated data in an understandable and easily searchable way. Their major weakness, though, is that they implicitly promise more than they can actually deliver. In essence, even though they are pretty good about disclaimers, they aren't good enough.

One of the first things the company should probably do is to reorganize the first page that potential customers see. They need to make sure that potential customers have a good idea about what they can and can't get from these sorts of genetic tests.

For example, right now a prominent feature is a box that lets the viewer search for the diseases 23andMe “covers” along with a list of popular topics. People may come away thinking 23andMe has useful tests for most of the diseases listed. They don't.

They have some useful tests for a few, rare genetic diseases. But the bulk of their tests are not at all useful yet in figuring out someone’s risk of getting a certain disease. What they have for the more complicated diseases is a way for people to compare their DNA to various studies in the scientific literature.

Maybe a study was done that found a DNA difference involved in diabetes. Customers can see whether or not they have this difference too but this tells them nothing about their risk for diabetes. It gives just one piece of a giant puzzle. They are not getting any meaningful results that can predict their risk for diabetes. This box should probably be heavily modified or even eliminated.

In fact, the website really should be organized into different sections that are labeled by how medically useful they are to the customer rather than by how strong the DNA study was scientifically. Maybe they could split their tests into three sections.

The first would be carrier testing. These tests can tell you if you have a hidden genetic disease that you could pass down to your child if your partner has it as well. This would get high marks for reliability, scientific validity, and usefulness.

The next section would be more fun related stuff. This would have ancestry and some of the traits testing. It would be able to tell you what your earwax is like, where your mother's, mother's, mother's, etc. mother came from, the odds that your child might have blue eyes, etc.

The final section would include the bulk of what is tested. These are the tests that compare your results to results in the scientific literature for complex diseases. Many of these tests would score high in scientific validity but get no points for usefulness. As I said before, most if not all of these tests will not give you an accurate risk assessment for the diseases they look at. Period.

There isn’t any reason these results shouldn’t be included, though. Maybe people enjoy seeing the results or want to use them to watch progress in the field or whatever. But the companies need to say upfront that these tests are not that useful for determining risk. This needs to be obvious enough that someone wouldn't buy the product just for that test.

As a last point, 23andMe (and all genetic testing companies) need to be much more upfront about what their tests can offer based on race. The carrier tests are probably pretty good for most everyone (although they may miss any nonwhite versions of many diseases). The fun section might be pretty useful to the nonwhite world for ancestry but probably less so for traits as they have mostly been determined for people of European descent.

Most of the rest of the tests they offer that deal with more complex diseases have only been validated for white people. This needs to be explicit on their website so nonwhite people know they aren't getting as much bang for their buck. Buyer of color beware!

These kinds of changes will go a long way towards making these sites more transparent to potential customers. And they may even keep the FDA at bay.

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Could you guess what this is from one of its hairs? That’s about how predictive current genetic tests are for complex diseases like prostate cancer or heart disease.

As I talked about in my last blog, direct to consumer (DTC) genetic tests are taking a beating right now from the FDA. Part of the problem has to do with some snake oil salesmen contaminating the whole field. But part of it has to do with the data that is available right now and how it is presented.

In this blog, I’ll deal with the data itself and why the FDA has such a problem with it. Next blog I’ll try to come up with ways to still get that data to consumers without ruffling any regulatory feathers.

A big problem with some of the current tests is that people will get different results based on the company they use. For example, the FDA reported that the same man was told he had an increased risk, the usual risk and a decreased risk for prostate cancer depending on the company he used. The FDA hates this kind of stuff.

To them (and many people), these kinds of results say that these tests aren’t working correctly. And given their experience with medical testing, they’re right.

A real medical test should give consistent results. If you take a test that looks at your cholesterol levels, your heart attack risk should be the same no matter who administers the test. Or if you take a genetic test to see if you are a carrier for sickle cell anemia, then again the results should be the same no matter who does the testing.

The genetic test for prostate cancer isn’t anything like these tests because it isn’t a medical test at all. It would be kind to even call it a work in progress. It is really just some interesting information at this point.

This is because we don’t have a good handle on the genetic risks for prostate cancer risk. There are almost certainly lots of different glitches in lots of different genes involved in increasing someone’s risks for getting prostate cancer. All of these variations need to be factored into a man’s risk for prostate cancer. And we only know about a few and those few have a pretty limited impact.

To add to the problem, different companies also look at different glitches or SNPs. So one company might look at one or two SNPs and say a man has a 1.2 fold increase in getting prostate cancer. And another might look at a different two and say he has a 1.1 fold decrease in getting prostate cancer. Different results but neither is particularly meaningful in predictive sort of way.

It is a little like trying to figure out what an elephant looks like from just the tip of its tail. And comparing that result to someone using an elephant’s eye lash to figure out the same thing. Odds are you’re not going to end up with the same animal. Just like you won’t end up with the same result from these kinds of genetic tests.

So when you have one of these tests done for complicated diseases like prostate cancer, diabetes, back pain, heart disease, etc., you’re only getting one piece of genetic information when you need 10 or 100 to figure out your actual risk. You have the eyelash or the tip of the elephant’s tail instead of the whole skeleton.

Now I don’t want you to walk away thinking that I am advocating that these companies shouldn’t give customers these results. I’m not. People should have a right to this information if they want it.

What I am advocating is that these companies come up with some way to explicitly state that these kinds of results are not useful medically. They need to be careful how they present the tests they offer and how they present the results. They don’t want to inadvertently lure customers into taking a test that can’t give them what they want.

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We put this story on the calendar back in September, before melamine-tainted milk started making headlines in China (with some products turning up on Asian grocery store shelves here in the US. Find KQED reporter Oanh Ha's excellent reporting on that story here, here, and here). We'd been planning to focus on criticism of FDA's handling of imported fresh produce, and had to recast the piece when it became clear that the concerns around food safety were much broader.

Another plan was shelved when the FDA declined to let us visit any of their local facilities, including a testing lab in Alameda that had been scheduled for closure only a year ago – right around the time that Mexican jalapeno peppers sickened 13,000 people and devastated the domestic tomato industry. (Officials blamed tomatoes before narrowing in on the peppers.) Luckily, the press office from the Bureau of Customs and Border Patrol generously agreed to show us around a Port of Oakland warehouse, where –- I quickly discovered — there were no FDA inspectors to be found. That's because FDA inspectors do their Port work largely in front of computer screens, scanning shipping manifests for products they believe warrant physical inspection.

That means two things: One, the FDA relies largely on the exporters' own description of what's in the product. As several people told me, it's an "honor system." Two, almost none (less than one percent) of the imported produce is ever tested for salmonella, e.coli, or any of the other human health threats we worry about.

When we finally talked to FDA Director of Food Safety David Acheson by phone from Maryland, he made the point pretty clearly: FDA knows its food safety program needs work. But that's going to require more and sustained funding. It'll be interesting to see how well the agency can make that case come January.

Listen to the Food Safety radio report online.

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Organic Fed / Certified Organic

All organic eggs are certified by the USDA. Organic eggs come from hens whose feed is free of pesticides, herbicides, fungicides, and commercial fertilizers. Organic chicken feed contains no animal byproducts and the hens have never been given antibiotics.

Hormones and Antibiotics:

The FDA banned the use of hormones – most notably diethylstilbestrol, or DES – in poultry in 1959, after they not only caused tragic health problems in consumers but also failed to stimulate growth in chickens. "Hormone free" is a misleading bit of marketing that suggests other egg producers are illegally dosing their birds.

Kept in Cages

Some hens are kept in battery cages; enclosures so small the animals can't spread their wings. Battery caged hens are crammed as many as six chickens into a cage at a time, leaving each bird with less personal space than a sheet of ordinary notebook paper. Critics say the battery system causes the spread of disease, requires the painful de-beaking of birds, and restricts natural bird behaviors, such as dusting or nesting.

Have Access to Outside

"Free Range" and "Free Roaming" are terms that bring to mind idyllic barnyard scenes. These labels, which are regulated by the USDA, may be used by a producer if their hens are allowed some access to the outdoors. This does not guarantee constant access, nor is there any specification of the size of the outdoor area (which is, of course, a penned area, not a range).

Beaks Clipped

Also known as debeaking, or beak trimming, is a process by which parts of the beak of a chicken or turkey are trimmed. Many variations of debeaking are used. Most commonly, the beak is shortened permanently, with the lower beak somewhat longer than the upper beak. The goal of this is to reduce cannibalism in stressed-out bird populations, such as in crowded egg-laying hen houses.

Forced Molted

When light and temperature are manipulated so hens lay eggs more than normal.

Omega-3 enriched

Omega-3 is a polyunsaturated fatty acid considered crucial by some for developing brains and preventing heart disease and depression. Farmers boost the omega-3 content of their hens' eggs by adding ground flaxseed, algae, or even fish oil to the birds' feed.

My own kind choice is to stay informed, shop at the local farmers' market and ask questions, and someday, raise my own.

If you have any tips or insights into local egg farms, please do share!

For more egg carton terms, go to:

http://blog.pennlive.com/naturalliving/2007/06/eggs.html

Amy Gotliffe is Conservation Manager at The Oakland Zoo.

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