Obviously, the more information you can provide, the more results you will receive. But not everyone has access to all of their ancestral information. . Digging up various info about yourself can be time-consuming and downright impossible for some. That’s why it’s important to look for services that are flexible with how much information they’ll require from you.
For better ancestry and medical insights, you should encourage family members, especially parents and grandparents, to take a DNA test as well. If your family is from a specific geographical location for generations, your samples could potentially improve the service's reference panel, in turn improving results for everyone. If you’re female and take a test from 23andMe or LivingDNA, you can view paternal haplogroup information, and you get more information when one of your male family members takes a test as well.
If you opt in to DNA Relatives, you will be able to send and receive invitations to connect with other customers who share DNA with you. You can choose whether to respond to these invitations or not, and your DNA relatives have the same choice. We cannot guarantee that they will respond to your sharing invitations or messages. Regardless of whether you both agree to share, you will be able to see their birthplace, locations of their ancestors and surnames, if they have chosen to add this information to their profile. If you both accept sharing invitations, you will be able to see ancestry reports and overlapping chromosome segments.
The 23rd pair of chromosomes is comprised of sex chromosomes – X and Y chromosomes that determine whether you’re male (XY) or female (XX). Traits like red-green color blindness, male pattern baldness and hemophilia are specifically linked to X or Y chromosomes and are called sex-linked characteristics. All of those examples, and most other sex-linked traits, are X-linked and more common in males, who only have one X chromosome. Many DNA tests isolate Y DNA in males to show consumers their paternal haplogroup. Since the Y chromosome is directly inherited from father to son, it is possible to trace direct paternal lineage for many generations.
If the company responsible for running your test is sold, whatever you signed loses significance due to the privacy policies of the company. Despite most of these privacy policies stating they will notify you of any changes, you would have to keep in constant contact with the company to ensure you were actually aware of these changes. The people willing to do this would be far and few between. Unfortunately, even if your name is not located within the database, this does not mean other databases cannot be used to determine your identity. In one specific case, a woman had a DNA test run. She found out she had a half-sibling. Although she was very excited about this news, this type of information would devastate numerous individuals.
Haplogroups are a different story. Your maternal line haplogroup assignment is derived from a separate piece of DNA called the mitochondria. Since mitochondria is passed on only by mothers to their children, your maternal line haplogroup assignment only tells you about your mother's side of the family. Similarly, the paternal line haplogroup assignment is derived from a different, separate piece of DNA called the Y chromosome. The Y chromosome is only passed from fathers to sons and only traces the paternal line.
Specific tests for your father’s family include ‘Y-DNA’ tests which focus on the ‘Y chromosomes’ in your cells’ nuclei, passed down from father to son. Specific tests for your mother’s family include ‘mtDNA’ tests which report on a subset of DNA found in the ‘mitochondria’ (your cells’ energy factories), passed down from mother to son or to daughter.