Reading Time: 32 minutes
For those interested in tracing their family history, DNA testing is the perfect route to take. Also known as genetic ancestry testing or genetic genealogy, it makes a way for people to move past family anecdotes or historical documents to actually unearth what is hardwired in their DNA and live longer. Wondering if genetic testing is something you could attempt? Then read on to know what DNA testing is all about, the types of tests, the costs, benefits, and risks involved and just how you can get started.
DNA Testing: What Is It?
For those intrigued and eager to know more about family history or genealogy, it makes sense to go for DNA testing. Examining the variations in DNA can provide clues regarding whether a person's ancestors hailed from a certain part of the world and the true relationships among family members. Specific patterns of genetic variation are shared among individuals of certain backgrounds. The more closely related two individuals, populations or families are, the more is the pattern of variation in common. Genetic or DNA testing specifically tests for mitochondrial DNA, Y chromosome testing or testing of SNPs/single nucleotide polymorphism testing.
In the case of Y chromosome testing, variations in the Y chromosome, which are shared by father and son, can be used to trace paternal lineage. Y chromosome testing is on males. But women who want to learn about Y chromosomes in their family can recruit male members for this test. Y chromosome testing is often used to study whether two families with the same last names are indeed related.
On the other hand, mitochondrial testing identifies genetic differences in mitochondrial DNA. Cell structures like mitochondria carry their own DNA known as mitochondrial DNA, although most of the DNA is found in cell nucleus chromosomes. Males, as well as females, have mitochondrial DNA passed on from the material side, so this test is carried out for either sex. It specifically provides information about the mother's line of genetic inheritance. This type of DNA testing is essential for tracing maternal genetic lineage because information about female ancestors married into the family is otherwise lost.
Single nucleotide polymorphism testing is for evaluating variations in SNPs across the individual's entire genome. Results obtained are then compared with others to determine the individual's ethnicity. Patterns of SNP may denote how much of ancestry can be denoted to African, European, Asian descent or unknown regions. This type of testing is used to capture overall ethnic backgrounds, rather than single ancestral lines.
Once the decision is made regarding DNA testing, a team comprising a medical geneticist, primary care doctors, nurse practitioners or specialists can carry out the test. Genetic testing is often part of a genetic consultation. This is why genetic tests are performed on samples of skin, hair, blood, amniotic fluid/fluid surrounding the fetus during pregnancy or other tissues. A procedure called buccal smear uses a tiny brush or cotton swab to collect cells of samples from the cheek's inside surface. The sample then reaches the lab, where technicians look for chromosomal, DNA or protein changes based on the suspected condition or disorder. Screening tests for newborns are carried out on small blood samples, by pricking the heel of the baby. Unlike other types of genetic testing, this result is received by parents only if it is positive, in the respect of the baby having a genetic disorder and additional tests needed to determine this.
Prior to the genetic testing, it is important for individuals to understand not just the testing procedure, but also the limitations and benefits, as well as possible outcomes of test results. Before carrying out a DNA test on an adult, scientists have to obtain permission or informed consent.
DNA: Know More
It was as early as the 1940s when DNA molecules were recognized as passing down generations of families. But it was only in 1953 that Watson and Crick came up with the chemical structure of this DNA molecule as a double helix or twisted ladder comprising 2 strands. DNA is formed in all cells of the body, serving as a blueprint. DNA strands contain information as codes that then serve as building blocks of individual characteristics and traits. The genetic code is essentially the order of 4 types of building blocks of DNA. Essentially, when the helix or double strands of the DNA separate, each base or building block templates a corresponding base on a fresh DNA strand. So, the information in the human body is never lost. Instead, it is duplicated and preserved.
DNA essentially stands for Deoxyribonucleic Acid. Testing for similarities in DNA samples allows familial bonds to be ascertained with remarkable scientific precision. The most common DNA test is the paternity test used to establish if a man is a child's biological father. There are, however, other uses for DNA testing as well. DNA testing is known as genotyping as it includes human DNA sample forensic analysis.
Decoding Your Genes: What You Need to Know
The order in which DNA bases occur is referred to as the DNA sequence. Each and every individual is unique and as individuals differ in their fingerprints, so too is the uniqueness of their DNA sequence. Half of a person's DNA comes from each parent. While fingerprints cannot reveal much, minor differences in DNA sequence can help in unearthing the distinct characteristics and traits of individuals. All the body cells contain DNA, as do skin cells from the cheeks' lining. These provide a convenient source of DNA testing material.
DNA in these cells is studied and minor variations are read out as a bar code by a machine. When net DNA barcodes from families are placed next to each other, it becomes clear the child is related to biological parents, as half the stripes in the bar-code-type signature match the mother and the other half match the father. In the absence of biological links, DNA signatures from a child and a parent are not 50% in common. DNA testing remains one of the most convenient, accurate methods of determining relationships.
Besides parental testing, DNA tests are also used for forensic testing to help identify suspects or victims in criminal cases. Gene therapy is another reason for DNA testing, to help parents or fetuses to be tested for genetic birth defects or mutations. Genetic genealogy remains another common reason for DNA testing.
At the core of DNA testing is a molecule DNA which carries the human genetic code and determines traits from personality to eye color. Every cell in the body from the heart to the skin, blood or bone contains a complete DNA set. The double helix of the DNA is a long, twisted ladder. The rungs of this ladder comprise four molecule pairs called nucleotides. While thymine (T) and adenine (A) bond together as a pair as do guanine (G) and cytosine (C). The genetic code comprises 3 billion pairs. 99.9% of the DNA from two individuals are identical. But it is 0.1% of the DNA code sequence that varies across individuals and makes each person unique.
The sequences are known as genetic markers and are part of the code that forensic scientists use while carrying out a DNA test. Identical or monozygotic twins are the only pair to have identical genetic markers. The more closely related two individuals are, the more likely it is their genetic markers will be similar or the same. At the heart of DNA testing is knowing where to look within billions of letters of the genetic code to locate genetic markers to identify important differences or similarities between individuals.
Parental, forensic and genetic testing checked similarities in genetic markers between 2 biological samples. All cells in the human body contain exactly the same DNA, and so, all the samples can be taken from anywhere in the body including hair follicles, skin, blood and other bodily fluids. A forensic scientist may compare DNA from skin cells beneath the fingernails of the attack victim, while the DNA from the potential suspect's blood samples may be compared to these.
DNA is isolated from the cells and millions of copies are made using a method called polymerase chain reaction/PCR. PCR uses naturally occurring enzymes to copy stretches of DNA repeatedly. Lots of DNA make the genetic code easier to analyze. DNA molecules are further split at certain locations into chunks and the code at specific points creates a DNA fingerprint. Further, the DNA signature from the two samples is compared to determine if these match.
The Accuracy of DNA Testing
The precision of DNA tests has massive implications. DNA tests are often the only evidence to prove suspects were involved in crimes or someone had been incorrectly convicted. While it is easy to tell if the DNA from 2 biological samples don't match, a match does not make it totally certain the two samples are coming from one individual. There is a tiny chance that different people may have the same genetic markers, especially if related. For reducing chances of error, scientists test more than a single genetic marker. The more identical markers are in a sample comparing two individuals, the higher is the accuracy of the test.
However, testing markers take time and incur an expense. Forensic DNA tests examine six to ten markers. The chance that 2 unrelated individuals have the same profile is less than 1 in 1 billion. DNA testing follows a procedural sequence, in which DNA or the genetic material is extracted from the cells of the patient, usually through a blood sample tested in a lab for changes. While DNA changes are usually suspected of triggering a disorder, DNA testing is used to gather information critical for healthcare.
DNA is essentially a large molecule comprising strings of smaller molecules. Diseases occur due to mutations in the DNA. A mutation leads to one or greater number of small molecules to be missing or changed in one or both strings. When mutation concerns one of the small molecules, though, the techniques for finding the alteration are tough, considering there are over 3 billion small molecules in every person's DNA.
Another extreme is when mutations involve large DNA segments visible under the microscope. Numerous lab tricks and techniques are used for detecting the smaller mutations. DNA tests are for constitutional or genetic mutations. These are mutations which are genetically inherited and present since birth in all the body cells. A readily available source of living cells can be tested. Blood cells are most commonly used, whereby the blood is drawn from the human body into a glass tube containing preservatives like EDTA in liquid form or acid-citrate. The blood specimen is drawn at local labs and mailed to reference labs. Until the reference labs receive many specimens and process these, the test is not completed.
In certain cases, mutations are focal in that they are present only in certain body cells or tissues. An example of such a mutation is one that causes a tumor. DNA changes that cause a tumor occur only once in cells that make up the tumor and not in other bodily cells. Additional steps in the testing process may, thus, be required. A tissue biopsy must be surgically obtained and simple mechanisms are not enough for preserving the tissue. Freezing it in liquid nitrogen or other special procedures need to be followed.
When is DNA Testing Needed?
A DNA test may be needed for several reasons, most of which are listed below:
#1 For Accurate Diagnosis
Ensuring the accuracy of a disease diagnosis medically is the most critical reason for DNA testing. Many diseases occur in forms that are difficult to detect. Some diseases or medical conditions may be so similar at least initially, that it may be difficult to recognize these. In other cases, different diseases may be similar so it is difficult to decide which is present. It is important to be clear about the diagnosis to choose the correct mode of treatment. Prognosis or knowledge about which symptoms the disease will trigger can make a difference to survival. There are different genetic mechanisms that cause diseases to take place in relatives or kids, too.
#2 Prevent Worsening of Symptoms or Disease
Occasionally, DNA tests can prevent or delay the disease. There are indications for DNA testing when no disease occurs. In families where genetic diseases are known to exist, DNA testing is able to identify whether relatives may contract the disease. In certain groups, genetic disorders may be so common that testing may be carried out on every family member. This is testing with the greatest value if there is an intervention that can prevent the disease, or even delay it. This could be an intervention like medication, surgery or even lifestyle changes.
If no intervention is available, testing of this kind can discover whose children could be impacted. In some cases, there may be prenatal DNA testing to assess if the fetus is impacted by the disease. Preimplantation DNA testing is done on early embryos as a consequence of in vitro fertilization to select those free from a particular genetic disorder. As many additional procedures are needed, preimplantation testing is costly and usually not covered by insurance.
#3 Assess if Individuals are Carriers
Carriers are persons without a particular genetic disease but those who can pass on the mutation that triggers the disease to their children. Carrier testing can serve to evaluate individuals whose family members are known to have genetic diseases or family members of identified carriers. It is also used to assess whether group members may have higher carrier rates for particular diseases. Carrier testing identifies individuals who have a mutation for a disease inherited in a recessive, X chromosome-linked or autosomal recessive manner. While the mutation does not cause diseases in carriers, it increases the chances of transmitting the disease to kids. Carrier testing also helps parents to make informed decisions regarding conception and family planning.
#4 Meet Social or Legal Requirements
There are also legal and social indications for DNA testing, especially if paternity is uncertain. DNA testing can identify the biological father. This is critical for determining the responsibility for child support or financial aspects of inheritance. When family history is incomplete or inadequate, DNA testing can determine even if genetic diseases exist in kids put up for adoption. DNA testing can also be used to discern genetic diseases in medical malpractice suits. Product liability defenses are yet another area where social or legal requirements need to be met.
#5 Organ Transplantation
Testing the DNA zygosity can be used to identify donors for organ transplants. Identical or MZ twins are generally the best donors. DNA banks are also offered by labs carrying out DNA testing. The DNA banks are created when DNA is extracted from the cells and frozen or refrigerated for further testing. DNA is stable even outside of the cells and can be stored for many years. DNA banks are a lifeline for terminally ill individuals with known or diagnosed genetic diseases or those with genetic disorders who cannot or do not want to opt for DNA testing.
Interpretation of DNA testing reports is generally straightforward but may require some knowledge of disease and genetics processes. Different mutations in different locations of the DNA lead to the same disease, so the mutation range of genetic diseases can create problems. Most DNA tests are specific in that a test for one mutation may miss a different mutation in the same gene. The absence of proof is not considered evidence of absence in genetic testing.
Testing for some genetic conditions needs linkage analysis. Rather than searching for the exact mutation causing disease, the linkage is based on testing for harmless mutations that surround DNA areas where the disease-linked mutation occurs. Linkage analysis also detects disease-causing mutations of different types but testing relatives accurately determine the DNA mutation areas. However, this incurs cost and loss of privacy possibly with the disclosure of non-paternity posing considerable risk. Further, the normal process of crossing over of DNAs during the production of the ovary and sperm cells in parents can come in the way of an accurate analysis of a child's DNA. Linkage analysis remains a gamble, and an expensive one at that as a requirement of testing for mutations in several people poses a challenge.
However, there's a bright future in DNA testing. Thousands of mutation tests can be programmed into a single computer chop. This increases ease of testing and accuracy. Many genetic diseases are rare so demand is not high. Techniques to test for mutations in all genes are required to overcome the hurdles and make DNA testing generally applicable.
Presently, DNA testing is available for over 400 genes implicated in genetic conditions or disorders. This number includes numerous cases in which same or similar diseases result from different genes, so an actual number of genetic diseases for DNA testing is much lower. For example, there are DNA tests for 12 genes that differ and are implicated in epidermolysis bullosa. There are clinical differences in the symptoms and forms of this disease, so all 12 tests may not be considered. However, all genetic diseases are listed in the OMIM at NIH. OMIM stands for Online Mendelian Inheritance in Man. Further, there are large national referral labs like Mayo Clinic and LabCorp that offer frequently used tests and are on contract with local labs. There are 400 certified clinical DNA testing labs. Online lists are available for healthcare providers.
Types of DNA Tests
Autosomal DNA Testing
Autosomal DNA is one that does not lead to differences in sex. This constitutes the first 22 pairs of chromosomes. As it does not rely on the 23rd pair, autosomal DNA testing can be carried out for both genders with the same results. Essentially, these tests examine single-nucleotide polymorphisms or SNPs or different patterns/shapes/sizes of individual nucleotides or small DNA chunks. Genealogy-linked autosomal DNA testing examines close to 700K SNPs to assess how closely you are related to another person. While half the DNA is from the father, half is from the mother. So, going back, roughly 1/4th of the DNA is from grandparents, 1/8th from great grandparents and so on. The further one goes back, the less DNA is inherited from a certain ancestor and it becomes harder to prove you're related.
Autosomal DNA testing, therefore, is only useful up to 4 to 5 generations back. They could link you with relatives like 3rd or 4th cousins, but not beyond that. The main use of this DNA test is to evaluate how closely related you are to someone else. This is useful if you know about your grandparents or parents to a limited extent and are unable to locate living relatives. Many times, relatives located by test research family lines too. Consequently, autosomal DNA can provide ethnicity estimates or at least trace where your ancestors lived. Companies that provide this testing divide the world into 20-25 regions, giving an estimate of what percentage of your ancestry comes from each. Companies like Living DNA and National Geographic offer this test.
Mitochondrial DNA Testing
Mitochondrial DNA testing also is known as mtDNA for short, is when genetic material or DNA within the mitochondria is tested. These are small components found within cells which have separate DNA strands. Essentially, mtDNA is passed down from the mother. As it does not contain a combination of DNA from both sets of parents, it does not vary across every generation. Further mitochondrial DNA changes gradually remaining the same for up to dozens of generations.
This form of DNA testing does not consider the main cell DNA, looking at the mitochondrial DNA instead. It means tests have to examine close to 16.5K genetic base pairs, instead of the 3.2 billion base pairs in the DNA. The test studies specific portions of the mtDNA and compares them to samples established. This then yields precise, accurate ancestry results, though only for the maternal line. It tells you about your great grandmother and grandmother and so on, back through time. However, this cannot tell you anything about your father's ancestors.
Further, mtDNA examines how closely related you are to haplogroups. These are essentially groups of individuals with the same ancestor. Everyone living in the same region may belong to one haplogroup or closely linked ones. The haplogroup further identifies where the maternal line originated. This helps in locating distant relatives some of whom could be really far off. Consider that mtDNA is the same for over 50 generations and a perfect match could mean you're related, but really distantly. FamilyTreeDNA offers individual mtDNA testing.
Y-Chromosome DNA testing
The 23rd chromosomal pair has two versions namely X and Y. Women have two X chromosomes, while men have an X-Y pair. Y-chromosome DNA tests examine only y chromosomes. As this is inherited from father to son, it changes very little across time. There are 2 sub-tests with Y-chromosome DNA testing.
STR: This is also known as the short tandem repeat test. The STR test categorizes sections of DNA as per how often a certain genetic pattern repeats itself.
SNP: This is the single-nucleotide polymorphism test. It is conducted the same way as an autosomal DNA test, and only tests 30K SNPs instead of 700K.
While the STR test produces a haplotype summary, it also offers the advantage of comparing someone else's results to see how long ago your common ancestor survived. An STR test is used to study if two people with the same last names are indeed related. The SNP test is more detailed and assigns individuals to a haplogroup.
Both these Y-chromosome tests can, therefore, help you to locate relatives. Like mtDNA, however, you could be really distantly linked, as the Y chromosome changes gradually. Also, the Y chromosome is passed down through males. So, the test can only reveal the direct paternal line. The only company to offer individual Y-chromosome DNA testing is FamilyTreeDNA. Others like National Geographic bundle this test.
Thus, the three main DNA tests are for direct paternal, direct maternal and ancestral lines, depending on which one you opt for. Each test examines a different DNA part.
How Each Type of Test Works
Y-Chromosome DNA tests
Such Y-DNA tests compare the male's Y chromosome marker with those of other males tested and matches males with the same or similar Y-chromosome DNA. It is relevant to paternal or male lines and the surname line, as it is called. Only males can test for this because males have a Y chromosome. Y-DNA testing can assess if the male descends from the same line, or another, rather than the direct paternal line. This is a paternal line DNA.
This is a maternal line test, that compares a person's mtDNA with that of others who have also tested and match individuals who share the same or similar mtDNA. This is relevant to the direct mother's line as everyone inherits mitochondrial DNA from the mother's side. Males cannot pass on their mtDNA. But they can test for this. A mitochondrial DNA can determine if you have descended from the same women ancestors as someone else tested. King Richard III was identified as descending from the royal line when his skeletal remains were unearthed in 2012 using this mtDNA test! So, for scientific historians, this form of testing is a boon.
Autosomal DNA Testing
Autosomal DNA testing or atDNA tests compared autosomal DNA of an individual with that of everyone else in the testing company's database. The company then provides you a list of individuals who match the DNA you have, with estimated relations based on shared DNA percentage. Autosomal DNA testing matches relatives on all ancestral lines, as each individual inherits this DNA directly from parents and forefathers or ancestors. So anyone, of any sex or age can be tested using autosomal DNA tests. Matches are strongest and most precise for immediate generations and close family, but sometimes matches can be found up to 6 generations or even further.
Autosomal DNA testing also sometimes include X chromosome matches. X-DNA matching tests can be useful, as certain genetic inheritance patterns come directly from this chromosome. Males inherit this chromosome from the mother while females inherit this from both parents. Identifying DNA relations as X-matches serves to identify shared ancestors relating to particular branches of the family tree.
Autosomal DNA tests also include predictions of ethnic composition, known as the admixture. These include maps of ancestral population clusters and regions, as well as estimated percentages. These are accurate at the broad continent level but vary across sub-regions. As reference databases are updated and developed, results are automatically updated. Each testing company presents reports differently, at different levels of confidence across different duration and periods of time.
DNA tests remain one of the most popular ways to open the doors and solve mysteries that no records exist for. DNA never lies so you can be sure it's the perfect way to find your roots and your origins. Tests such as autosomal DNA were once considered junk DNA tests, However, scientists soon discovered it can be used for male and female line relatives across men and women subjects, Anyone can identify the possible relatives of any gender. Offering to test and comparing notes easily, this is one of the most popular DNA tests carried out.
Choosing A Test That's Perfect for You
With so many types of DNA tests to select from, how do you choose the best? It all boils down to what you seek to uncover.
For many genealogy experts, autosomal DNA tests are a clear choice. This is because this is one test every testing company offers. As autosomal DNA comes from different ancestors, this test is excellent for finding a range of living relatives and ancestors. It provides reasonable ethnicity estimates and lets you know regions of the world where your ancestors resided. The only problem? This test is so jumbled up after a few generations so much so that it loses reliability the further you go back. Autosomal tests are useful only up to 5 generations or till the great-great-great grandfathers or grandmothers. In terms of living relatives, at best it can stretch to 3rd or 4th cousins. However, autosomal tests can also provide great leads about who is researching the same family tree as you.
As mtDNA or mitochondrial DNA comes from the maternal line, it helps to trace only one line. It can be used to prove common ancestors in the direct maternal line. In spite of this limitation, mtDNA is useful to trace a line very long back, even tens of thousands of years. This provides evidence about how the mother's maternal line comes from a specific ethnic or regional group. However, it is less useful for locating living relatives and also is one of the costliest DNA tests out there.
Y-Chromosome DNA Testing
The Y-DNA test is like the mitochondrial DNA test in that it follows a single genetic line. The only difference is this test focuses on the direct paternal line. The Y-DNA test can reveal all you want to know about your paternal ancestors. This type of test is extremely useful if one seeks to prove a connection to a specific ancestor. Much like the mitochondrial DNA test, Y-DNA testing lets you trace back the line for dozens of generations. It also reveals a lot about the ethnicity or region of the paternal line. One drawback of this test is that males have Y-DNA so males can take the test. However, women can find Y-DNA results using their male relatives from the maternal line as test subjects.
Uncovering Origins and Ethnic Grouping
All of these DNA tests provide information on where ancestors lived. But they provide the information in different ways. While mtDNA and Y-chromosome DNA tests link you to specific genetic lines, these represent a fraction of the family tree. Autosomal DNA tests cover the entire family tree but get mixed up after some generations so estimates can only be provided. The companies offering DNA testing divide the world into regions in different ways. While most companies limit themselves to 25 regions or lower, the number, names, and location of the regions vary across one company to another. Two different testing companies offer different ethnic estimates for the same DNA, therefore. As more data is collated, companies may update their regions. The precision and accuracy of estimates are improving as more data is collected.
The DNA test also gives a region of origin, not a country. This is because countries have shifting boundaries, even within your own lifetime. On account of migration and intermarriages, being specific is hard.
Getting Started with DNA Testing
If you are considering having a DNA test, there are a lot of steps you need to work on, including which company works best for you, the cost, the duration of time it takes and much more.
Basically, DNA is collected with a saliva sample or cheek swab, depending on which company is used. For the most part, one method does not have any advantages over another. If a person being tested is too young to provide a saliva or too old to be unable to produce enough saliva, the cheek swab is easier. While companies like AncestryDNA use saliva samples, others use cheek swabs.
Once the DNA sample has been gathered, it needs to be returned to the company for further processing, whereby it takes 6-10 weeks for samples to be processed. It could take longer during peak seasons like holidays where DNA testing is often gifted. Once the test is complete, one can be emailed with the results. Depending on the test and company, results include raw data, estimates of ethnicity and ways to study potential relatives.
Prices often vary depending on the test or company. It can also be purchased as a gift for your loved ones.
Choosing the Right Company
There are so many companies available for genealogical DNA testing. All these sites offer autosomal DNA testing, providing a geographical breakdown of where ancestors have resided. Choosing a DNA testing company depends on what type of test you want. Here are the possible reasons for opting for a test:
Such estimates help to answer who the individual is and where ancestors come from. Through DNA analysis and comparing this with numerous regional sample groups from across the world, DNA tests can provide correct ideas about where your ancestors hailed from. Different companies provide different levels of locational accuracy, depending on how extensive the databases are and the level of sophistication of the analysis.
Ethnicity testing works to offer accuracy in results on a continental level and also certain historically and genetically isolated groups like Ashkenazi Jews or Native Americans. On a more localized level, results become tougher to decipher, as free people movement within continents has obscured differences across populations. It is also easy to pinpoint a small percentage of DNA in an individual's genome, but less easy to assign DNA majority to specific countries. Location accuracy is, however, constantly improving. Assigning the origin to over 350 distinct regions across the world is now easy.
This answers who are the living relatives and specific ancestors. DNA tests also reveal relatives you never thought you had. Major testing companies have relative location tools. DNA testing can even identify recent or long term ancestors in the family tree. This can take you far back into the past, especially if living relatives are performing the same kind of ancestry research.
Assessing Health Risks, Carrier Status, and Wellness
DNA tests help to answer if children face higher risks for specific ailments or diseases. By comparing the DNA with genetic markers detailed in scientific literature and research, DNA tests can predict risks of developing health problems like dementia, cancer or age-linked macular degeneration. Testing for health risk factors can offer truly valuable information to make better medical decisions and take on preventative measures.
Some companies offer an additional service known as Wellness Report. This report offers information that does not indicate specific genetic conditions but can help in understanding how to experience better sleep, addiction tendencies, natural genetic weight or the possibility of lactose intolerance. The information further helps in guiding individuals in terms of lifestyle and diet. Carrier status reports are also carrying genetic variants that do not impact just your health, but the health of your family's kids too. If both parents are carrying a disease-causing variant for cystic fibrosis, for example, there is a one-fourth chance that each kid will inherit the disease, because this requires the genetic variant to be present in both parents.
Trait reports can pinpoint everything from whether you have fast or slow twitch muscles to how sensitive you are to caffeine. Trait reports are amazing and created by consulting scientific literature and determining how selected genetic markers correlate with others taking the test and answering lengthy questions. From chin dimples, to taste preferences and even odor detection capabilities, there's a lot you can unearth through DNA testing.
Submitting Your DNA: Steps to DNA Testing
Submitting your DNA samples is simple. All you need to do is take saliva or a swab from the cheek and the lab carries out the rest of the work. The key step in the extraction process at the lab is isolating the DNA so it is in a pure form.
The next step is when the DNA material is placed onto a machine, where its analysis is undertaken by a DNA genotype chip. Chips target specific genetic markers, namely short DNA sequences around SNPs. Once the sample is genotype analyzed, its information is loaded onto a data system. Further, you are sent a report outlining what the DNA says about you.
Types of DNA: Understanding the Basis of DNA Testing
DNA in our bodies can be grouped into different categories.
The human body comprises 23 pairs of chromosomes in the nucleus of their cells. Of the 23 pairs, 22 make up what is known as Autosomal DNA. This means DNA is contained on 22 pairs of chromosomes and it is not integral to determining the gender of the individual. Moreover, one copy of each chromosome is inherited from each parent.
Autosomal DNA forms the basis for all the information one can learn from DNA testing, as it covers 22 of the 23 chromosome pairs. Further, it offers information about ancestry, traits, ethnicity, and wellness as well as chances of developing diseases. Autosomal DNA is coming from both parents. Both men and women can have autosomal DNA tested. Most DNA service providers offer these DNA tests. It is one of the most popular, common types of DNA analysis.
Y Chromosomal DNA
The 23rd pair of the chromosome is unlike the others. It is called the sex chromosome pair. The pair determines if one is female or male genetically. In most cases, a person inherits the X chromosome from the mother and X or Y from the father, depending on whether they are daughters or sons respectively. There are rare genetic diseases where other combinations can be seen. As only males have a Y chromosome, this chromosome and its associated Y-DNA is passed to sons from their fathers.
Y-chromosomal DNA tests are only available for men as against women who lack a Y chromosome. This allows male customers to get greater inputs in their paternal line's ancestry. Y-DNA is useful because it does not involve a rearranging process referred to recombination, unlike other chromosomes that are rearranged and reshuffled between each and every generation. Women can opt for paternal relatives like fathers, paternal uncles, brothers, and paternal male cousins were to have the genome tested. One can predict the lineage from such reports.
Mitochondrial DNA is extremely unusual as it emerges from the energy-producing factories known as mitochondria in the cells, instead of the nucleus. Further, mtDNA is shaped in a circular form and is passed from mother to child. Male kids carry their mother's mtDNA but do not pass this onto the children, who inherit it from their mothers.
Mitochondrial DNA makes up a small proportion of the human genome. It also does not reveal much about the traits one is likely to have as the purpose is solely to control the cell's energy-producing processes. However, mtDNA can provide in-depth information regarding ancestry and is useful for this reason. As mtDNA is inherited exclusively from the mother and does not recombine, analysis of mtDNA allows scientists and geneticists to trace your maternal lineage and more so, through hundreds of generations. Males, as well as females, can take the mtDNA tests. Only the ancestry of the mother needs to be investigated.
So, while autosomal tests are perfect for connecting the family tree or understanding the admixture and which tribes you belong to, while Y-DNA tests trace the paternal line and mtDNA tests trace the maternal lineage. There are also X-DNA tests that should only be considered matching when profiles share at least 10cM or centiMorgans.
Which DNA Test is Best?
Here are the factors that come into play when deciding which DNA test is best for you.
#1 Trace Ancient Ancestry
DNA testing companies use autosomal DNA to trace ancestry back to 100s or 1000s of years. Autosomal testing is used to create admixture reports also known as ancestry composition report. This report breaks down ancestry background into ethnic percentages. This offers a comprehensive understanding of the ancient ancestry. One of the key advantages of including everyone in the family line is that no one is omitted.
#2 Finding Close Relatives
For this purpose, choose the autosomal test. This test is really accurate for close family members like first cousins and siblings but gets more ambiguous as one advances down the line. Autosomal tests, therefore, go up to the 3rd or 4th cousin level at most. Beyond this point the DNA derived does not lead to reliable predictions. Autosomal DNA tests further do not identify which side of the family the match is from. Family trees, surnames or chromosome browsers can be used for this purpose.
#4 Verify a Sibling/Cousin Relationship
For understanding the relationship between siblings or cousins, an autosomal test is most effective. It tests the relationship between 2 siblings. The test studies the amount of DNA shared. For siblings, the match should be anywhere from 2400 to 2600 centiMorgans/cM or around 50%.
#5 Verify or Investigate Your Paternity
For this, it is important to get a Y-DNA test. As this DNA is passed down from the father, the Y-DNA test is the ideal choice for those who want to study and explore their paternity. FOr verifying paternity, the lab will compare Y-DNA STR marketers against those of the males to be verified as the father. The Y-DNA is passed down unchanged, except for rare mutations from the father. So, the 2 DNAs should have similar markers. Y-DNA can also be used to verify family links with other paternal relatives like a grandfather, male cousin or uncle. If you are researching the paternal lineage, this test explains which haplogroup you are coming from, as well as the migration patterns.
#6 Research or Verify Your Maternity/Ethnicity
To verify or research the maternity or long-term ethnic history, get an mtDNA test. Mitochondrial DNA is passed down only from the mother. Like Y-DNA testing, it never changes meaning it can be traced back to many generations. Use mtDNA testing to assess your maternity or maternal family line. It can be used to find close members on your mother's side using FTDNA only.
How It Works
Online DNA testing takes anywhere from six to eight weeks. You also don't need to go to a lab or clinic to be tested. The process of DNA submission is painless, simple and takes just a few seconds. After the order for the test kit is placed online, the testing company mails a kit used to collect DNA samples. Both cheek and saliva swabs provide a reliable sample.
After the sample is collected, it needs to be secured as per instructions offered. Make sure the sample reaches the lab safely.
DNA testing can take up to 8 weeks. This is because DNA testing is complex and takes time. Labs produce hundreds of samples on a weekly basis. The high volume of orders can delay your report further.
Results are available in a couple of weeks through a secure online account. Emails notifying when the results will be ready will notify you in advance. Once you log into your account, you can view the DNA matches, read admixture reports and get access to various tools for getting the most out of test results.
Cost of DNA Tests
DNA testing kits have become really popular and a major cause for this is the affordability of these kits. The kits are painless, easy to use and well-priced. There are many types of DNA test kits available. A key differentiator is a price. Kits mostly reveal a lot about your genetic history and answer questions. These kits are competitively priced. They are also accurate and reliable, with a large and diverse database.
Prices depend on the company and the test. Autosomal tests run up to USD 79 to 99. Companies may offer separate Y-DNA and mtDNA tests averaging around USD 199 for mtDNA and 169-359 for Y-DNA. It also depends on the genetic markers used. All three tests are bundled for USD 150-159 by some companies. But such bundled tests may be less detailed than individual tests.
Health reports additionally, can assess if the genes for different diseases or conditions are active. Companies also charge USD 10-12 dollars for shipping. Most companies run sales from time to time. While some kits focus on testing only certain parts of the DNA and give information about genetic diseases, others look at ancestral history and trace the family back 10 generations or higher. When selecting a DNA kit, it is important to study the questions and keep the budget in mind. Affordable DNA kits cost less than USD 70, in some cases. Cost of DNA testing is affordable for many individuals. This is due to the popularity of the DNA test. Testing is used to determine paternity or relationships. The DNA testing is presently mainly carried out for ancestry inquiries, paternity and health reasons. Testing for health reasons is limited to patients concerned about inheriting certain diseases and discussing these with healthcare professionals. Now people carry out genetic testing for different types of health concerns, whether family history is known or not. DNA testing has dropped in cost.
When it comes to the cost, though, it will depend on the reason for testing. Paternity tests are more basic, costing less than for ancestry, with court-approved tests costing USD 500 and nonapproved tests pegged at USD 70. Testing for disease markers costs more, due to testing and interpretation extent. DNA paternity tests are the least expensive. Couples who need to identify the child's biological father can do so with a non-approved test for a small fee. Approved tests are available in a day ort wi.
Paternity Testing: Cost
Cost of paternity testing ranges from USD 69 to USD 399, based on the lab and test type. Results for the same day cost around USD 245. Few labs provide same-day results. There are many more that provide results within a day or two. Some US labs can take up to a week to provide paternity test results. Labs that take up to a week for paternity test results can price services near the lower end of the range. If one goes through with the test post a sample, a free DNA test kit may be provided for a litigation or paternity lawsuit. A cheap or free DNA testing kits can answer questions about paternity before deciding to take a case to court.
Ancestry Testing: Cost
DNA testing for tracing your ancestors is becoming popular. Testing for ancestry reveals different types of information. The first kind of data it reveals is ethnicity. Most people think of one ethnic origin, but there are many ethnicities found in their genetic makeup. This feature may matter to those who are adopted, and keen to know about their antecedents. Sometimes, ancestry testing can reveal specific types of disease or health problems and prove useful for those working to diagnose a condition with a healthcare professional. Ancestry DNA testing can connect distant relatives. This testing costs anywhere from USD 69 to 1399. The fees at the higher end include other forms of DNA testing in association with a genetic disease or health markers. For those who do want to know where they are coming from, testing is not costly, Most companies offering ancestry testing take 4 to 12 weeks. Some companies in the US have resulted in under 2 weeks. However, the price is not dependent on the duration for results. When testing for DNA results are sometimes offered as historical narrations, too. Along with this, the reports provide information on how many individuals are there with the same genetic markers and how these are geographically distributed.
DNA Testing for Health
For those undergoing a test, DNA testing for health is totally worth the money. There are many reasons to test for genetic or inherited health issues. This also provides physicians the most complete view of health, in case there is a risk of passing conditions down to children. Some genetic diseases like Huntingdon's Disease impact adults in the prime of their life. Family members need to guard against such diseases. This also matters for carriers considering children or those without a biological history due to adoption being tested for medical conditions.
Many families opt for having children tested. Any of the diseases affected by genes are known as being 100 percent penetrant. So, knowing about the condition in advance can prove helpful. Some diseases can be a consequence of a combination of genes, behavior, and lifestyle. It benefits you to know your propensity for such diseases. DNA testing for health and genetic diseases were earlier expensive for many individuals. Now, they are more affordable. Cost of testing for health conditions can range from below USD 100 to more than USD 2000 depending on the kind and complexity of the test. The cost rises further if more than one test is needed or multiple family members must be tested to obtain meaningful results. For newborn screening, costs vary across states. Some charge around USD 15 to 60 per infant.
The doctor ordering the test can also shed light on the cost and time frame, depending on the nature and complexity of the test.
Benefits of DNA Tests
For many disorders, genetic testing is the only way to make an accurate diagnosis and avoid unnecessary clinical studies. Genetic testing can guide clinical personnel about the most suitable therapy and support for the patient. A definitive diagnosis can be relief inducing for family members and patients, especially if answers have been sought for a long time.
In certain cases, genetic disease surveillance and early intervention can save the life of the patient, such as early diagnosis of hereditary or genetic cancer. Further, the result of genetic tests can be used for future family plans.
The accuracy and precision of genetic tests are crucial. Major life decisions are based on genetic test results. So, genetic testing should be performed by accredited, quality labs that assure quality outcomes and have quality control measures in place. Ideally, patient care should also include pre and post-genetic counseling to explain options and outcomes and obtain informed content.
Genetic tests have the potential to benefit individuals whether results are negative or positive for the gene mutation. Test results can further offer freedom from uncertainty and help individuals to make informed medical decisions. A negative result can prevent unnecessary screening and checkup tests. A positive result can also direct individuals towards preventing, monitoring and treating options. Certain test results can also make family planning decisions easier. Newborn screening can reveal genetic disorders right from the start and treatment can commence as quickly as possible.
So, whether you are at risk for Alzheimer's or Parkinson's, there's relief in knowing the science of genetics lets you end the guessing game. Researchers in the past decade completed the Human Genome Project, mapping 25K genes in the human genome. This important step in genetic science produced massive DNA data that gave people an idea about the DNA inherited from the family. Genetic or DNA tests allow individuals to form health plans in advance.
The DNA test could reveal you have a genetic condition or disease or a predisposition to it. Armed with this, your doctor can help you to prevent triggering the disease. The test further confirms the genetic condition and also helps in proper disease management. Tests also screen for markers associated with chronic, life-threatening diseases.
A genetic or DNA test can also identify enzyme deficiencies and associated mutations. A genetic test also makes it easier to manage health concerns and go past making your DNA your destiny. Epigenetics is a science of studying gene expression and managing genes through a combination of food, supplements, environmental exposure, stress, exercise, and sleep.
If your genes were tested in infancy, using epigenetics, you can plan for medical care, nutrition and lifestyle choices to silence genes that damage health and optimize healthy genes. Serving as a window to health outcomes, DNA tests can firmly place your well being in your hands. Genetic labs have made testing easier.
Further, a genetic test can tell certain facts about your genetic makeup. The accuracy of diagnosis is assured making appropriate treatment easier. There will be a better chance of finding the right support. Even in the event of family planning, genetic testing can provide useful information. As genetic disorders run in families, genetic makeup composition is easy to unearth with DNA tests. Whether you want to understand your family tree, recognize health conditions, or even predict future conditions, genetic or DNA testing is important.
Risks of DNA Testing
Taking a genetic test, getting results and interpreting these are harder than you think. While genetic tests may confirm a diagnosis, treatment or intervention may not be medically possible. Some genetic mutations are also tough to discover using DNA testing. For those trying to get a diagnosis, this can be tough. Discuss the issue with the doctor, because for some conditions, the exact intensity of symptoms or onset of diseases can be tough to predict.
Genetic mutations are passed through families. Results of your genetic test could prove to reveal information about other family members particularly the genetic risk of the condition. Other family members may not want to know about this.
DNA tests can impact insurance cases and even reveal family secrets like adoption and paternity. Once the results of a DNA test are revealed, there is no returning to the status quo. It is important to discuss with a genetic counselor or trained healthcare professional because a discussion can make things easier.
Physical risks are minimal, especially for those where the tests only require a blood sample or buccal smear. Procedures for prenatal testing, however, carry a small risk of miscarriage because a sample of amniotic fluid or fetal tissue is needed.
Risks associated with genetic testing include social, emotional or financial consequences of test results. People can feel negative emotions about their results. Genetic testing could also create tension within the family.
The possibility of genetic discrimination in employment or insurance can also be a real problem. Further, genetic testing provides limited information regarding inherited conditions. The test cannot determine if the symptoms will actually manifest, the severity of symptoms and the progression of the disorder over time.
Genetic testing forms are providing consumers with unprecedented access to DNA data and privacy risks may not be understood by customers. The federal government, as well as law enforcement, can pressure companies to share DNA data.
Test providers may compare individual test results to different databases of previous tests so ethnicity may be inconsistent from one database to another. As human populations have migrated many times, ethnicity estimates derived from genetic testing may be very different from what you expect. In case of smaller variation range in ethnic groups due to history and size, individuals may share many SNPs and isolating a common recent ancestor may be harder than you think.
Genetic testing is offered by organizations and companies. On a larger scale, scientists may also be testing genes and this can have a lot of implications, depending on how the research is used.
Obviously, hacking is another concern the genetic testing industry is facing. DNA data could easily be breached. Often, you may not profit on your DNA, as DNA data could be shared with research partners and even corporate pharma and medical groups. Further, laws concerning genetic privacy are not well established in many countries, the US included. The only law covering genetic privacy is the Genetic Information Non-Discrimination Act or GINA in the US. So, you could end up finding your ancestors but losing your privacy in many cases.
Further, many tests do not even examine a majority of the DNA. If there are millions of SNPs, DNA database uses only 100 to 300 genetic marketers. This has limitations in terms of accuracy of findings. Moreover, the findings may even be used for non-research purposes. The question of bioethics is largely an unchartered territory right now.
Even with the risks, people should consider DNA testing for the immense benefits genetic testing offers. Like medical information, it is always best to do research beforehand and chose the best firm for the job. All DNA results cannot be 100% true, but most of the data will offer an important understanding of who you are and a window to your past, present and ultimately, your future. Checkout more information at TestMedna.com.