Home DNA Test Kits - Worthwhile? Expert Opinion Needed

In summary, the conversation is discussing the use of home DNA testing services, specifically the 23andme service, and whether it is worthwhile or not. The experts in the conversation agree that these tests are not reliable and do not provide enough information to be useful. They suggest that for medical reasons, it is better to consult with a family doctor or genetic counselor. Additionally, they mention that these tests often look at gene variants rather than mutations and do not take into account a person's genetic background, making them even more unreliable. The experts also mention that in the future, genome sequencing may provide more informative results. Overall, the consensus is that these tests should only be done for fun, not for medical reasons.
  • #1
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Has anyone used a home DNA testing service? I was looking at 23andme service. The reviews are pretty good and it's only $100. Could be interesting. What do you experts think? Worthwhile?
 
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  • #2
In my genetics department we regularly review literature on studies where disease risk is predicted based on genetic defects. Long term follow-up studies are still lacking, but it is clear that commercial kits can not full-fill their promise.

If you have a 50% increased chance of getting a disease, does that sound scary? What if you knew the disease only has a prevalence of 0.001% in the population, a 50% increase suddenly sounds a lot less pressing right?

If you have a very serious genetic disease running in your family, go to a family doctor and ask for genetic counseling. Otherwise, live healthy and save that 100 bucks for the future where the tests could become more reliable. That's my opinion. In a few years you can get your entire genome sequenced for that price. Don't expect that to be the holy grail either, things are not that straightforward as we thought at the beginning of the century when the genome sequencing started :wink:
 
  • #3
Monique said:
If you have a 50% increased chance of getting a disease, does that sound scary? What if you knew the disease only has a prevalence of 0.001% in the population, a 50% increase suddenly sounds a lot less pressing right?

I agree with Monique based what I know about these tests. However if the test was reliable and it indicated a 50% chance of having a gene for a disease, the relevant probabilities are 50% and the probability of developing the disease, given you have the gene. I realize that Monique was talking about a 50% increase in the risk, which would not necessarily involve a specific gene, but a predisposition due to other risk factors.
 
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  • #4
I'm not convinced by the utility of getting your DNA sequenced, if it is needed for medical reasons it can be done anyway like Monique says.
 
  • #5
I would get a DNA test for fun, not for medical

besides, medicine is just a theory : )
 
  • #6
Thanks for the advice! I would be doing it just for kicks! Maybe I will wait a little longer in order to get more clear results.
 
  • #7
SW VandeCarr said:
I agree with Monique based what I know about these tests. However if the test was reliable and it indicated a 50% chance of having a gene for a disease, the relevant probabilities are 50% and the probability of developing the disease, given you have the gene. I realize that Monique was talking about a 50% increase in the risk, which would not necessarily involve a specific gene, but a predisposition due to other risk factors.
I'm not sure if I'm following you there, but most of the tests use numbers that are not easy to interpret by the person receiving the results.

Also, often multifactorial diseases such as "cardiovascular disease" are mentioned: because they are most prevalent in populations. The pitfall is determining the risk there is not easy and different companies who provide the test will give different results based on the genes tested.
The gene mutations that are known to cause disease with high penetrance are usually the rare ones, as said: you'll probably know whether they exist in your family or not.

Another pitfall is that these tests often don't look at mutations, but at certain variants that are associated to a disease: the underlying cause is unknown. Whether the variant is predictive depends on your genetic background (e.g. asian or european decent), this is not taken into account in the tests, even further making them unreliable.

A big effort has been underway to gain more insight in the meaning of a person's DNA, I'm sure the future will be more informative. Our department will be implementing a version of genome sequencing for diagnostics soon, an interesting development. I doubt the patients get to take their sequence home though.
 
  • #8
Monique said:
I'm not sure if I'm following you there, but most of the tests use numbers that are not easy to interpret by the person receiving the results.

Also, often multifactorial diseases such as "cardiovascular disease" are mentioned: because they are most prevalent in populations. The pitfall is determining the risk there is not easy and different companies who provide the test will give different results based on the genes tested.
The gene mutations that are known to cause disease with high penetrance are usually the rare ones, as said: you'll probably know whether they exist in your family or not.

Another pitfall is that these tests often don't look at mutations, but at certain variants that are associated to a disease: the underlying cause is unknown. Whether the variant is predictive depends on your genetic background (e.g. asian or european decent), this is not taken into account in the tests, even further making them unreliable.

A big effort has been underway to gain more insight in the meaning of a person's DNA, I'm sure the future will be more informative. Our department will be implementing a version of genome sequencing for diagnostics soon, an interesting development. I doubt the patients get to take their sequence home though.

Going back to your first post, you indicated that a 50% increase in the risk for a disease has be considered in terms of the prevalence of the disease. So if the prevalence is 0 0010 of the population, than a 50% increase the risk based on the prevalence would indicate a risk of only 0.0015. This is true. I was only saying if having specific gene was associated with a known risk for a disease, then the presence or absence of that gene is the relevant factor, not the prevalence of the gene or disease in the population.
 
  • #9
I'm curious... do these tests tell you about expressing or just having?
 
  • #10
The types of DNA tests that these commercial services use look only at whether certain gene variants are present in an individual's DNA. The tests provide no information as to whether that particular gene variant is expressed. Figuring out whether the gene variant is expressed is a tricky question, however, because the answer to that question will vary depending on what cell type in the body you test.
 
  • #11
Pythagorean said:
I'm curious... do these tests tell you about expressing or just having?
I mentioned that for those tests often causative mutations are not taken into account, but variants/markers that are associated to a disease. I often challenge the geneticists to perform functional studies, but that takes times.

SW VandeCarr said:
I was only saying if having specific gene was associated with a known risk for a disease, then the presence or absence of that gene is the relevant factor, not the prevalence of the gene or disease in the population.
Ok, but if you know the result of a test then you don't know whether you will get the disease or not (except for Mendelian diseases with 100% penetrance). So it always needs to be correlated to a population prevalence, some people carry risk genes that increase their chance of getting a disease. If the tests tells you that you have a variant that increases your risk of colon cancer, I think you would want to know what that risk then is.

The test will likely say you have a % increased risk, it probably won't say you have a % risk. Maybe Greg should give us feedback if he takes the test, how the results are given :smile: You need to be aware that relevant risk is more often used than absolute risk, because it sounds more dramatic and thus sells better. I guess the same reason that people often use SEM as an error bar, instead of 95%CI.
 
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  • #12
Monique said:
Ok, but if you know the result of a test then you don't know whether you will get the disease or not (except for Mendelian diseases with 100% penetrance).

For the most part, this is what I was talking about. There's a short list of genetic diseases where the defect type and location are known, and a much longer list of genetic diseases where the specific defect, location or both are not known. Collectively, they represent a significant burden of disease in many populations. Since most are likely autosomal recessive, it may be useful to test potential parents to assess disease risk in any children they might have when such testing is reliable and inexpensive. In this case, prevalence, disease severity, treatment options for the child and family history are all considerations. However for the affected individual, the prevalence in the population doesn't matter. For any reliable test which places the individual in a higher risk subgroup, it is the disease prevalence in that subgroup that is relevant.

http://en.wikipedia.org/wiki/List_of_genetic_disorders
 
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  • #13
Greg Bernhardt said:
Has anyone used a home DNA testing service? I was looking at 23andme service. The reviews are pretty good and it's only $100. Could be interesting. What do you experts think? Worthwhile?

It might be fun, yet I wouldn't consider it an informative endeavor. As Monique points out, most of the diseases we (in the West are most worried about), like coronary artery disease or metabolic syndrome, are so convoluted through multifactorial risks that just knowing your "predisposition" (if one could even go so far) wouldn't be all that helpful.

You'd be better off just reading a list of the top 20 ways people in the US die then altering your life style based on modifiable risk factors associated with those causes of mortality. For example, smoking.

SW has a good point though in that it could be useful for (as Monique puts it) 100% penetrate disease--Like those that follow simple Mendelian inheritance. I think if you have one of these diseases, you likely already know--So in that regard it might not be so useful. But are you a carrier for cystic fibrosis? I don't know if I am (though a negative family history for both my wife and I, and 3 healthy children would be a good indicator I am not), but some of these companies will tell you if you are (though with CF there is an ever increasing amount of mutations associated with the disease alleles, and I doubt any of these companies test for more than the top 5-10).

I think a "more fun" DNA test might be the ones that "trace" ancestry through population based SNPs. That might be more worth your money for fun's own sake, in my opinion.
 
  • #14
Thanks all! Bob 23andme also does the ancestor stats too. Apparently good enough to find up to 5th cousins
 
  • #15
Greg Bernhardt said:
Thanks all! Bob 23andme also does the ancestor stats too. Apparently good enough to find up to 5th cousins

I got a free test a couple of years back because I was doing an article on the whole deal.

I'd say do it for fun. It could also potentially pick up something useful. I got no particular surprises except an increased risk of haemochromatosis. The sort of condition you would never know about normally, and is good to be alerted to just on the off-chance.

The ancestor thing is also fun. Trace your mom and dad back before the last ice age. You will definitely find a lot of 5th cousins with no conceivable connection, but fun to chat to.

Generally I think the site handles the science side of their findings very well. At $100, its easily worth the admission price.
 
  • #16
Greg Bernhardt said:
Thanks all! Bob 23andme also does the ancestor stats too. Apparently good enough to find up to 5th cousins

I'd definitely do it, but I have more personal reasons. See, my dad was raised Mormon, and they are very good at tracing ancestors. Thanks to their work I have a very nice family tree all worked out. But curiously, they have little information about my dad's mother.

Looking at pictures of her as an elderly woman, she looks like she may have African heritage. A test like that would pick that up, I think.
 
  • #17
Greg Bernhardt said:
23andme also does the ancestor stats too. Apparently good enough to find up to 5th cousins

Be ready for some surprises.

The more DNA testing, the more divorces.
 
  • #18
Borek said:
Be ready for some surprises.

The more DNA testing, the more divorces.

Haha good one :)
 
  • #19
Borek said:
Be ready for some surprises.

The more DNA testing, the more divorces.
I was doing genetic testing a few years ago in the States, of families volunteering to participate in a scientific study. I sometimes ran into families where it was clear that the child must've been conceived by another man than the listed father. I always wondered whether any of the parents knew that was the case :uhh:
 
  • #20
I ended up going for it! Just sent in my test tube of spit :) I'll report back in a few weeks with a review!
 
  • #21
Greg Bernhardt said:
I ended up going for it! Just sent in my test tube of spit :) I'll report back in a few weeks with a review!
Please note we don't provide diagnoses here :tongue2:

In all seriousness it will be interesting to see what you find out, in particular what the company highlights.
 
  • #22
Interesting development about 23andme:

http://www.bbc.co.uk/news/technology-25100878

The US Food and Drug Administration has imposed a ban on a company offering personal genetic screening to the general public.

Google-backed 23andme has been ordered to "immediately discontinue" selling its saliva-collection tests after failing to provide information to back its marketing claims.

...

In a public letter the FDA said that 23andme had not supplied this information, despite increasing its marketing campaign and the scope of its tests.

"FDA is concerned about the public health consequences of inaccurate results from the PGS device - the main purpose of compliance with FDA's regulatory requirements is to ensure that the tests work," said Alberto Gutierrez, director of the FDA's centre for devices and radiological health, in a letter to the company.

"Patients relying on such tests may begin to self-manage their treatment through dose changes or even abandon certain therapies depending on the outcome of the assessment," he added.

While this certainly does have a "nanny-state" smell to it which I don't like, I see FDA's point. If the people ordering this test don't know how to interpret it, and they are making medical decisions with the data, that could be a problem. Or if they don't have enough relevant information to correctly interpret it due to marketing, that could be borderline fraud (e.g. if the company isn't releasing information because it would negatively affect sales).

Sticky problem. I wonder what 23andme is going to do about this?
 
  • #23
It may go deeper than just a "Nanny State" situation.

The astigen-1 gene appears to be involved in muscle damage caused by statins. Statins are a multi- billion dollar industry.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2735363/

I have read a number of articles about people who have quit taking statins and headed to alternative medicine sources. The link below is from 23andme and describes one patient's experience.

But over the last few years, Richard noticed he was experiencing muscle problems. His doctor didn’t seem too worried, so at first Richard didn’t push it.

But all that changed when Richard took the 23andMe test last summer. His results at once surprised him and made sense. According to his 23andMe report he was at risk for developing muscle myopathy due to the use of statins.
23and me has a good read on a sidebar about not stopping meds because of anything found in the genetic tests.

http://blog.23andme.com/23andme-customer-stories/keep-on-pushing/ [Broken]
 
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  • #24
My take-away is that Greg never revealed the results of his spit test... :smile:
 
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  • #26
Here was the email sent to me

Dear 23andMe Customers,

I wanted to reach out to you about the FDA letter that was sent to 23andMe last Friday.

It is absolutely critical that our consumers get high quality genetic data that they can trust. We have worked extensively with our lab partner to make sure that the results we return are accurate. We stand behind the data that we return to customers - but we recognize that the FDA needs to be convinced of the quality of our data as well.

23andMe has been working with the FDA to navigate the correct regulatory path for direct-to-consumer genetic tests. This is new territory, not just for 23andMe, but for the FDA as well. The FDA is an important partner for 23andMe and we will be working hard to move forward with them.

I apologize for the limited response to the questions many of you have raised regarding the letter and its implications for the service. We don't have the answers to all of those questions yet, but as we learn more we will update you.

I am committed to providing each of you with a trusted consumer product rooted in high quality data that adheres to the best scientific standards. All of us at 23andMe believe that genetic information can lead to healthier lives.

Thank you for your loyalty to 23andMe. Please refer to our 23andMe blog for updates on this process.

Anne Wojcicki
Co-founder and CEO, 23andMe
 

1. What is a home DNA test kit?

A home DNA test kit is a collection of materials and instructions that allow individuals to collect and submit a sample of their DNA for analysis without having to visit a medical facility or laboratory. These kits typically include a swab or tube for collecting a saliva or cheek cell sample, as well as packaging and instructions for sending the sample to a laboratory for analysis.

2. How accurate are home DNA test kits?

The accuracy of home DNA test kits can vary depending on the company and type of test being performed. In general, these kits can provide accurate results for basic genetic information, such as ancestry and basic health traits. However, they may not be as accurate as tests performed in a medical setting for more complex genetic conditions or diseases.

3. Are home DNA test kits reliable?

Home DNA test kits can be reliable for providing basic genetic information, but they may not be as reliable as tests performed in a medical setting for more complex conditions. It is important to research the company and read reviews before purchasing a home DNA test kit to ensure its reliability.

4. What are the benefits of using a home DNA test kit?

The main benefit of using a home DNA test kit is convenience. These kits can be easily ordered online and completed in the comfort of your own home. They can also provide basic genetic information, such as ancestry and health traits, without the need for a doctor's visit or expensive medical tests.

5. Are home DNA test kits worth the cost?

The worth of a home DNA test kit can vary depending on the individual's personal preferences and goals. Some may find the convenience and basic genetic information provided by these kits to be worth the cost. However, others may prefer more comprehensive and accurate testing performed in a medical setting. It is important to research and consider the potential benefits and limitations before deciding if a home DNA test kit is worth the cost for you.

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