Before ordering a DNA test or whole genome analysis, you should probably improve some of the biology terms you’ve long forgotten. But don’t worry! This guide will guide you through all the terms you need to understand when you get the results from a genetic home test directed at the consumer.
First, what’s DNA?
DNA is shortened to deoxyribonucleic acid. This molecule contains all the information that cells need to survive and reproduce. DNA is stored as chromosomes, and humans have 23 unique chromosomes. Each of these chromosomes contains the information necessary to produce various proteins, which work together in immensely complex networks to form a functioning body.
On each chromosome there are several genes. Each gene consists of small molecules called nucleotides. There are only 4 different nucleotides used: adenine (a), guanine (G), taurine (T) and cytosine (C). The mechanism of the cell reads these nucleotides in groups of three, called codons. Each codon reports a different command to the cell machinery, including commands for “STOP”, “START” and commands for each piece of the protein.
The codons together contain a replica of the basic structure of a protein. Proteins are composed of many individual amino acids, which are formed together as a chain to create a functioning protein. There are only 21 amino acids, and DNA nucleotide codons may require each specifically. These completed protein molecules then fold into unique forms, and have a variety of functions. Some proteins copy DNA, others hold cells together, and others are enzymes, which allow the cell to control chemical reactions.
All together the genes on your chromosomes are referred to as your genome. Your genome encodes all the proteins in your body, which in turn allow your cells to operate, grow and reproduce. Although the process is much more complicated than this simple description, This is easy to remember. DNA makes proteins complete cellular tasks.
When someone does the DNA test, scientists read the genetic code, down to the nucleotide sequence. Even if there are only 23 unique chromosomes, you get a copy of each chromosome from each parent. That gives you two copies of each gene. This is important, because each copy can have minor variations. These alleles form slightly different forms of the proteins that are created, which can lead to differences in function. By learning which alleles you carry, you can learn about how your genetics can affect your health and life.
How do scientists read DNA?
To read his DNA, the lab will need a sample. To obtain a DNA sample, most laboratories require a simple swab on the cheek. To do this, just drag a cotton swab through the inside of the cheek. Your cheeks are gonna spill on the swab, and from those cells, the scientist can extract your DNA.
The cells of the cheek are washed by the swab and pass through the process of DNA isolation. During this process, cell membranes are washed off, along with other cellular components. This leaves only DNA molecules behind. To analyze the DNA content, scientists must use the polymerase chain reaction, commonly called PCR.
Polymerase is a special protein that can replicate DNA. Using this protein, scientists can add a little heat and some free nucleotides. This allows the polymerase to replicate its DNA. This is important, because only a small amount of DNA was collected from the sample. After many cycles of this process, the lab will finally have enough material to start analyzing your DNA.
To do this, they first cut the DNA into recognizable small pieces. Then, they order the pieces according to the size, weight and electric charge. From these properties, they can understand to which chromosome the genetic material belongs, and to which genes it contains. Finally, scientists will use advanced computers to” read ” the pieces by identifying the individual nucleotides it contains. From this series of nucleotides, scientists can make some interesting conclusions about your DNA.
Things scientists learn by reading DNA
There are several areas that could be analyzed by a DNA test. First, testing companies are trying to identify which alleles of each gene you actually carry. This is done mainly on autosomal chromosomes. These chromosomes, other than your sex chromosomes, carry most of the information your body needs. The laboratory will analyze these genes to determine which alleles you carry, and the diseases and character characteristics that these alleles could lead to.
When scientists analyze the Y-chromosome (Y-DNA) of males or the mitochondrial DNA (MtDNA) of females, they are analyzing your relationship with the ancestral groups. The male Y chromosome has passed from father to son, and goes largely unchanged over time. Similarly, DNA found in mitochondria (a small organ that produces energy inside cells) passes from mother to relatively unaltered offspring over time. By comparing your DNA in these segments with others, the lab can identify which ancestral populations your ancestors belonged to.
Regardless of whether scientists are looking at autosomal or sexual chromosomes, they are looking for the same little things. Within the human population, each gene is composed essentially in the same form. However, as time drags on and DNA is replicated and copied, it can begin to accumulate mutations. Most often, these mutations are small single nucleotide polymorphisms (SNPs). This simply means that in the chain of many nucleotides, a single nucleotide is replaced with another.
These small genetic variations allow scientists to categorize and trace DNA over time, as well as identify some alleles without reading and translating the entire genetic code. Scientists can identify SNPs within your DNA, and they can identify which alleles you are carrying based on the SNPs present. Sometimes, the SNP will not alter the function of the final protein. These are known as silent mutations. Other times, the new nucleotide will accidentally end the short protein, known as a meaningless mutation. The mutation can also be mostly harmless, changing the protein only slightly. This is known as the missense mutation. By understanding the normal gene, scientists can predict how these mutations can affect the function of proteins.
Similar to these small genetic markers are short tandem repetitions (STRs). Unlike SNPs, these short repetitions contain many nucleotides, but serve as unique markers within the DNA. STRs are commonly used in criminal DNA testing, as unique markers to identify a person. The FBI, for example, uses a person’s unique nucleotide sequence in 13 different areas to identify a person with near-perfect accuracy. These short repetitions can also be used to identify various alleles or genetic conditions.
The lab will assemble all these things and build a working photo of his DNA. Their report should give you information about what alleles you carry, and how your particular DNA sequences can affect your health.
Things You Could Learn from a DNA Test
There are a lot of important things you could learn from a DNA test. In the first place it is a term known as vector status. Some genetic diseases, such as cystic fibrosis, afflict patients only when that person has two copies of the disease-related gene. In some cases, people can live a normal life while carrying a copy of the malfunction gene. These people do not have the disease, but they are known as carriers. Doing a genetic test will probably inform you of your carrier status for different genetic diseases.
In a similar line, many genes offer resistance to certain diseases, based on the actions of the proteins they produce. For example, sickle cell anemia is a genetic disease, but it also blocks the growth of organisms that cause Malaria. Laboratories can now test different genes that are known to have relationships with various diseases.
Your genetic test report probably contains a variety of other traits of genetic influence, and the specific alleles you carry. The ability to taste a certain bitter chemical is an example. With some alleles, you can taste the chemical. With other alleles, you can’t. Similarly, your report could show alleles related to lactose digestion (sugar inside milk) and caffeine metabolism. These traits biochemical reactions that are influenced in part by your genetics.
Besides, his blood type is genetically determined. Your blood type is actually a set of proteins that attach to the surface of the blood cells, allowing your body to recognize them. By reading your DNA, the lab will be able to give you an advanced look at exactly what proteins are produced.
Finally, the information from your sex chromosomes can determine many things about your ancestor. They can test your maternal or paternal haplotype. A haplotype is a genetic identity shared by large groups of people. Ancestry tests compare your DNA to the DNA profiles of the first humans while they migrated from Africa. Since Y chromosomes and mitochondrial DNA remain relatively unchanged over time, the laboratory can roughly identify when your ancestors migrated from Africa, up to about 200,000 years ago. They can also identify whether your ancestors broke up with Neanderthals, an extinct but separate species.
Now, What Do You Do With This Information?
Knowing your genetics is just a small step to complete your health. You may receive potentially devastating news. Maybe you have a gene that increases the risk of cancer. But don’t freak out.
More important than your genetics alone is a concept called epigenetics. Your epigenetics is your genetics, plus the environment you put them in. This is extremely important, more than your genetics alone.
As an example, we follow two people on their journey through life. Let’s say that as a child Marcy has a gene that increases the risk of breast cancer, while Ted does not. Given only this information, it is easy to say that Marcy has an increased risk of breast cancer. But it’s not even the beginning of the story.
Marcy lived an exceptional life. She ate Whole Foods, plant-based diet, and practiced regularly. Ted wasn’t so nice to his body. He smoked a pack of cigarettes almost every day, and regularly ate fried fatty foods. Now, which person is more likely to have cancer? The results of cancer studies would argue that Ted presents a much higher risk.
You see, regardless of the genes you inherited, a much more important factor is your lifestyle. In fact, the BRCA gene was hailed after it was found to be the” genetic cause ” of cancer. However, over the years since its discovery, its importance has diminished. Not only did scientists find other genes that can be associated with breast cancer, they also found that the BRCA gene is present in less than 20% of breast cancer cases. This means that 80% of the time the patient did not have the BRCA gene, but still had cancer.
Your epigenetics are therefore a much greater factor in your overall health than your genetics alone. Sometimes, DNA testing companies will refer to Nutrigenetics, a field that looks at your nutrition compared to your genetics. This can help you provide information about personal biochemistry that can help you make the healthiest decisions.