23andMe is a private organisation based out of Mountain View, California, and it was founded in 2006 to help people access, understand and benefit from the human genome. It is also the first and only genetic service available directly to customers that pass the FDA standards for clinical and scientific validity[1]. Named after the 23 pairs of chromosomes in the human cell, the company has already genotyped 3 million customers around the world.
Once you send your saliva sample to the lab, they identify who’s sample it is by scanning the barcodes on that boxes. They then ensure that enough saliva is contained within the tube in case they need to run repeats. They use an automated version of the standard process of DNA extraction that can also be done at home with some basic ingredients. The sample is then submitted for genotyping on the company’s custom SNP chip along with 95 other samples, and they try to achieve results for genetic codes with 98.5% of the markers that were tested for. After successful analysis, the lab sends the results to 23andMe with the appropriate barcode, and then 23andMe synthesizes the data and sends it to the customer online[2].
23andMe offers two types of packages to analyse this genetic code. There is first an option to choose which kind of test you would like to carry out. One is a $99 “Ancestry Service”, which provides the customer with 5 reports of their Ancestry, including their composition, maternal and paternal haplogroup, Neanderthal Ancestry and the DNA Family of the customer. The following is an example of an ancestry chart:
The second is a $199 “Health + Ancestry Service” that includes the primary 5 Ancestry reports, and then has a series of reports over and above that which gives the customer an insight into their health, whether they have an genetic predispositions to diseases, such as the risk of developing breast and ovarian cancers, celiac disease, Parkinson’s disease. They also offer “Wellness reports” that include information on genetic weight, lactose intolerance, muscle composition to name a few. Their “Traits reports” include information such as the person’s affinity for bitter taste, eye color and Toe Length Ratio to name a few[1].
Lastly, they provide the customer with a “Carrier Status report”, which gives you an insight into the genetic variants in your genotype that can cause inherited conditions. These are found primarily in certain ethnicities. This report can be fairly useful for information as to which conditions the person is susceptible to passing on to their kids, as carriers may not necessarily have the condition but they can pass it to their offspring. If the person is made aware of the fact that they are carriers for an inherited condition, it would be wise to not have kids with a partner who is also a carrier, as the likelihood of their kids having the condition becomes decently high. The test results will indicate to you whether you have 0 variants (very low likelihood of you having the condition), 1 variant (you are a carrier and could pass it to each child), or 2 variants (you are very likely to pass a variant on to each of your children)[2].
Some of 23andMe’s core values are to use data to revolutionize health, wellness and research. They do this to improve healthcare and prevent disease, and to give individuals control over their health data. In tune with this ideology, genetic testing has been around in some form or the other for centuries. The same way companies like National Geographic and 23andMe are testing peoples’ genomes and giving them information regarding their genetic preferences and conditions, humans were able to do this without knowing the genetic backing to their actions since we started taming dogs about 15,000 years ago in Europe and Central Asia[3]. By observing their pet dogs’ various phenotypes, they were able to selectively breed them in a process coined “Artificial Selection”. They would purposefully put two dogs of the opposite sex possessing the same desirable characteristic in the same place so that they would breed, producing a litter with more pronounced desirable traits. Through the 18thcentury we discovered that traits were linked to the chromosomes within our cells, in 1975 DNA sequencing was developed, and in 2003 the Craig Venter Institute finished sequencing the entire human genome with 99.99% accuracy[4]. The following chart summarises some of the benefits of genetic testing:
[3](Agence France-Presse 2016)
In the 1970s new-borns began to be tested for PKU (phenylketonuria) which is when an amino acid build-up in the blood causes mental retardation. If diagnosed with potential PKU, the children were put on strict dietary treatment in order to preserve brain function[1]. Subsequently, diseases such as sickle cell anaemia, Tay-Sachs disease, cystic fibrosis etc. Today, we are able to sequence a person’s genome and test them for over 2000 different conditions, including diagnostic, carrier (such as what 23adnME does), prenatal etc. However, there are several questions that must be answered before evaluating direct consumer DNA testing for health conditions. These are:
- Can the condition/symptoms be treated, prevented or lessened?
- Does evidence support the targeting of a test for a specific condition to a specific population group? If yes, does testing carry a stigma?
- What are the rates for false positives and false negatives?
- To what extent do test results predict severity of a condition?
- Are the genes tested the only ones that can cause a particular condition?
- Is the extent of genetic counseling provided suited to the seriousness of the traits or disorders[2]?
Despite the various advantages and obvious technological advancement that services such as 23andMe seem to provide, it is important to consider the viewpoints that deem services such as these as controversial. For one, the results come back with a percentage chance risk of developing the disease, and often times they are just single digit percentages. It is important to keep in mind that even if people have a mutation in their genes, for example the way 23andMe would test for Parkinson’s, even if they get a small chance of developing Parkinson’s, “by and large they won’t develop Parkinson’s disease”, said James Beck who is the chief scientific officer of the Parkinson’s Foundation[3].
On the contrary, if a patient receives their reports and they indicate that the customer is at no risk for developing rare disorders, it is by no means an indicator that the person is free of risk. For diseases such as Parkinson’s and Alzheimer’s, most of the risk of developing them is accrued from non-genetic factors or from genes that are in addition to the ones that 23andMe tests for. Even if the customer tested negative for all diseases, their risk may still be increased based on their family history[4].
Another very common fear for people is to get unnecessarily scared at the thought of contracting a disease that is listed on their results report. 23andMe is aware that this is one of the drawbacks of their genetic screening service: triggering a response from people that is unwarranted. The organisation warns that these tests “are about serious diseases that may not currently have an effective treatment or cure”, and in addition state that people that have been diagnosed with anxiety or depression may experience emotional difficulty as a result of the reports[5].
The idea of being able to identify your ancestral nationality just by spitting in a container is mind-blowing, and plays into the concept of countries and nationalisation that we learnt about. Countries are a relatively new concept, and have been around for far fewer years than our unique genetic combinations have. A reason why this is not necessarily an accurate way to determine where someone is from is due to the vagaries of country borders. For example, a north Indian person’s genetics are far more closely related to a Pakistani’s than from someone in South India. However, on the report the ethnicity “India” would show up even if they traced back to someone who was very close to the border, and therefore genetically very different from a south Indian’s, who will also receive “Indian” on their results.
As for the future of genetic screening services such as 23andMe, the potential applications are enormous as new genetic information will be translated into clinical tests for the diagnosis of current illness and prediction of risk of a disease, and can be used for developing genetically directed therapies and preventive interventions. The testing will become automated and will be used in more tried and tested moral and ethical manners[6].
Works Cited
23andMe. 23andMe Carrier Status Tests: What you should know.January 1, 2018. https://www.23andme.com/test-info/carrier-status/ (accessed April 15, 2018).
23andme. Our Science.January 1, 2018. https://www.23andme.com/genetic-science/ (accessed April 14, 2018).
23andMe. What Happens To My Sample At The Laboratory?January 1, 2018. https://customercare.23andme.com/hc/en-us/articles/202904590-What-happens-to-my-sample-at-the-laboratory- (accessed April 15, 2018).
Agence France-Presse. DNA evidence suggests humans may have domesticated dogs twice.June 4, 2016. https://www.telegraph.co.uk/news/2016/06/04/dna-evidence-suggests-humans-may-have-domesticated-dogs-twice/ (accessed April 14, 2018).
Begley, Sharon. Before you send your spit to 23andMe, what you need to know.April 9, 2017. https://www.pbs.org/newshour/health/23andme-need-know (accessed April 15, 2018).
Forumbiodiversity.Latin American 23andme results and charts.August 18, 2011. http://www.forumbiodiversity.com/showthread.php?t=45691 (accessed April 15, 2018).
Leonard, Debra G.B. The Future of Molecular Genetic Testing .May 1, 1999. http://clinchem.aaccjnls.org/content/45/5/726 (accessed April 15, 2018).
Lewis, Rick. A Brief History of Genetic Testing.May 5, 2008.
https://scienceprogress.org/2008/05/a-brief-history-of-genetic-testing/ (accessed April 15, 2018).
NIH. Frequently Asked Questions About Genetic Testing .January 1, 2018. https://www.genome.gov/19516567/faq-about-genetic-testing/ (accessed April 14, 2018).
—. Genetic Timeline.March 26, 2004.
https://www.genome.gov/pages/education/genetictimeline.pdf (accessed April 14, 2018).
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