If you’ve been on social media or reading news outlets, you might have noticed that many people are using DNA Ancestry kits as a fun way to learn more about their genetic profile and cultural heritage. DNA Companies such as and offer insight into a person’s genetic background from a simple DNA sample. Adverts have shown customers finding out about a “hidden” heritage that they didn’t know they had or one that they interpreted incorrectly ()! Learning more about the history behind your genome can shed more light on different things about you, such as medical history or the languages your family may speak. So, how do you go from a spit sample to a detailed report?
Buying a DNA kit directly from a DNA company is the easiest way to get your hands on one. Once you receive your kit, you dispense a sample of your DNA (typically saliva) into a collection tube. Once filled, you send the sample back to the company’s address, where it will be sequenced. The sequencing process involves converting your DNA into the letter “code” or “alphabet” that DNA uses – ATGC.
Once the DNA is sequenced, it can be analyzed for specific genes and possible mutations. The analysis of these mutations is where the bulk of your genetic profile report is coming from. After the analysis is completed, most companies will send you a confirmation email to access your test results online. The wait time between when you send in your DNA sample and when you get your results will vary between companies but can be anywhere from 4 weeks to 4 months.
The reason why it can take a while to sequence and then analyze your DNA is because your genome is so enormous. The term “genome” refers to all the genetic material contained in your cells, the typical DNA ancestry and health services only use your autosomal DNA in the analysis and report. Autosomal DNA is the genetic material that you can get from both parents’ autosomal chromosomes, and they code for everything except your sex organs.
Even without taking into consideration the sex chromosomes, DNA is still very extensive, having multiple regions that code for various things. Some regions, which scientists call “genes,” can code for specific proteins or a regulatory function. There’s actually not a specific definition of what a gene actually is since different genes can do different things.
While things such as eye colour and hair colour can be easier to trace back to a handful of probable genes, more arbitrary things such as your spice tolerance or what time you like to get up are more difficult to pin down. These phenotypes, a physical expression of a gene, can be determined by one or more mutations in genotypes, an allele that determines the expression of a specific trait.
Genotypes and phenotypes are much more complicated than are taught in introductory biology classes. We’re typically taught that genes come in different flavours or alleles. Phenotypes such as brown hair and blue eyes can be controlled by different sets of genes that are located on different chromosomes. Specific mutations, or variations, of these genes can cause different shades of brown hair or different shades of blue eyes. There are certain genes that are usually sitting close together on the same chromosome and thus get passed onto the offspring as if it was part of a matching set. However, this isn’t always case.
As stated earlier, genes can be regulated by various enzymes or other genes, and they can interact with each other! It’s because of this that trying to determine if there’s a predisposition to a certain behaviour or set of behaviours can get sticky. For instance, there are several suggestions for what could lead to a predisposition for depression, such as mutations located on genes coding for serotonin transporters and receptors, brain-derived growth factor, tryptophan hydroxylase, and many others. Even with this long list of possible reasons that could lead to depression, these genes only lead to a probability that MDD is the outcome for mutations in these areas.
DNA companies use these areas of mutations to try and find commonalities between different group of people who have lived in the same geographic location for a while. The thought process behind this is that if a group of people, such as Spaniards or Nigerians, have lived in that same geographic location for generations, then there must be some sort of natural selection happening where the environment is selecting for the “best fit” people to live there. Sometimes it can actually be the best fit or can just arise out of pure circumstance. For instance, civilizations who have lived closer to the equator will more than likely have darker skin due to higher rates of melanin production. Melanin is a pigment that protects your skin from the harmful UV rays of the sun.
People who live in warm climates, typically closer to the equator, will have a higher production of melanin in order to protect them from intense and painful sunburns. This is an example of a genotype and phenotype being selected from the environment.
So, there you have it, science and technology are able to turn a simple saliva sample into a detailed account of your family history and connections. This advancement gives you a great opportunity to unlock new personal insights and potentially find a cousin you didn’t know about… or even a sibling! Let us know your experience using DNA companies via email (firstname.lastname@example.org) or on our social media (@wonkscience).