Genealogy DNA test
A genealogy DNA test can be useful to you at the time of discovering distant relatives, uncover your ethnic mix and get a generalized picture of your ancestry from a genetic perspective. It can also be helpful at the time of finding where your ancestors might have come from, getting clues for finding your family coat of arms and to look for blood family in case of adoptions.
Why are we looking for this information?
Your results could be a smart starting point for more family history research or can be a way to dig even deeper into the research previously done. When a genealogy DNA test is checked against family history records, is a highly efficient resource at the time of helping you find your genetic ancestry and outline your family tree.
How does a genealogy DNA test work?
Chromosomes carry hereditary, genetic information in long strings of DNA called genes. Humans have 22 numbered pairs of chromosomes and a single pair of sex chromosomes—XX in females and XY in males. Each chromosomal pair includes one inherited from the father and one from the mother.
https://genographic.nationalgeographic.com/science-behind/genetics-overview/
This combination process makes it difficult to study lines of descent because it creates a genetic mix of everyone who has come before but fortunately, there are parts of the genome that are passed down unshuffled, and in these parts the genetic code is varied only through occasional mutations. When these mutations are passed down through the generations they become “markers of descent”.
Considering the above, three types of genetic ancestry testing are commonly used for genealogy purposes:
- Y chromosome testing: it is used to check the male branch and can be performed just on men. However, women can always recruit a male relative to have the test done. The Y chromosome is the sex-determining chromosome in humans: while all other chromosomes are found in matching pairs, it is the mismatch of the Y with its partner, the X chromosome, that determines gender. Y chromosome testing is often used to investigate questions such as whether two families with the same surname are related.
- Mitochondrial DNA testing: it is used to check the female ancestral branch. Mitochondria are self-reproducing structures responsible for generating most of the energy used by the cell. Because there are no mitochondria in the head of a mature sperm, they are passed down solely from mother. As both males and females have mitochondrial DNA, which is passed on from their mothers, this type of testing can be used by either sex. Mitochondrial DNA testing can be useful because it preserves information about female ancestors that may be lost from the historical records.
- Single nucleotide polymorphism Whenever a a “mistake” called “misspelling” gets introduced into the DNA sequence, it might be shared by a large number of people and is known as single nucleotide polymorphisms(SNPs, pronounced “snips”). DNA testing companies use the SNPs to estimate a person’s ethnic background among other things.
However, genealogy DNA tests face some limitations: due to chromosome recombination events, about 30% of your true relatives will not share any detectable DNA segment with you. But of course, through the relatives you share DNA with, you can jump above missing DNA links in your family and get a larger number of relatives.
What information do we need to gather to perform a genealogy DNA test?
- None: the way to run a genealogy DNA test is to take a saliva sample at home using a special kit provided by the company preforming the test.
- The main companies performing this test do not just provide detailed instructions with the kit but do also have on line tutorials to help you get your DNA sample by yourself.
- Together with the kit, a Release Form is sent to get your written consent that allows the company to share your name and email address with someone who matches your genetic fingerprint. This of course is optional.
Is it hard to get this information?
- You just have to request your kit to any of the companies engaged in DNA genealogy, take your saliva sample, submit the kit back, and wait for the results. The results are normally sent by e-mail within 6-8 weeks.
- Costs are accessible and vary from 99 to 150 U$S dollars, not considering mail fees and taxes.
What is the solution and why?
- Genetic testing services are being offered by several companies and organizations that also provide online forums and other services to allow people who have been tested to share and discuss their results with others.
There are three major direct-to-consumer DNA testing companies all US based:
- AncestryDNA of Ancestry.com
Check at: http://dna.ancestry.com/
- Family Tree DNA (FTDNA)
Check at: https://www.familytreedna.com/dna-test-kit.aspx
Family Tree is a partner of National Geographic.Geno 2.0 Project. Therefore, you can also check:
http://shop.nationalgeographic.com/ngs/browse/productDetail.jsp?npd&npd&productId=2003825&gsk-
- 23andME
Check at: https://www.23andme.com/en-int/
The top company is most likely Ancestry.com that gives you the possibility of checking your DNA against more than 700.000,00 genetic markers. Ancestry.com also maps your ethnicity going back multiple generations and including information about your ethnicity across 26 regions/ethnicities. Once your test is done, ancestry.com searches the network of ancestryDNA members and identifies the people who share your DNA.
The National Geographic Project is also very interesting and offers comparable ancestry-relevant information. Both Ancestry.com and National Geographic tests, combine the three types of genetic ancestry tests previously mentioned, while 23andMe’s test is more focused to identifying genetic markers (SNP´s).
Conclusion:
DNA testing has been questioned as a valid source of medical information. Its interpretation is difficult and often leads to anxiety and to unnecessary spends in medical testing, due to the big scope of diseases that might be potentially carrying our genes, even if at the end they do not “activate”. As science is advancing on a daily basis, future will tell if at some point, these tests can became useful as prevention and health care tools. However, DNA testing has already proven to be very effective from the genealogical point of view for identifying biological family, and in general, tracing family history.
By, Carmen Vazquez Sibils
