If you have your DNA tested and the test results indicate you are someone other than yourself, the cause might be something other than a mix-up at the DNA testing lab. Instead, it probably indicates the DNA that you are carrying in your body is not the DNA you were born with.
Did you ever have a bone marrow transplant? When you have an allogeneic bone marrow or stem cell transplant, the blood-producing cells in your bone marrow are killed off by radiation or chemotherapy and then replaced with functioning cells from the person who donated the bone marrow. The technical term for this process is allogeneic hematopoietic cell transplantation.
An allogeneic stem cell transplant is most often used to treat blood cancers, such as leukemia and lymphoma, and certain types of blood or immune system disorders.
This may explain “strange results” some people have found in their DNA tests.
You can read more about allogeneic hematopoietic cell transplantation in a number of online articles:
DNA Testing After a Stem Cell Transplant: a Fascinating Case in the WaterShedDNA web site at: https://www.watersheddna.com/blog-and-news/stemcelltransplantgedmatch
Getting a bone marrow transplant could give you new DNA, too in the MedicalXpress web site at: https://medicalxpress.com/news/2018-01-bone-marrow-transplant-dna.html
Hematopoietic stem cell transplantation in Wikipedia at https://en.wikipedia.org/wiki/Hematopoietic_stem_cell_transplantation
Transplant patient’s DNA is ‘replaced’ with that of his donor in Yahoo News at https://news.yahoo.com/transplant-patients-dna-is-replaced-with-that-of-his-donor-124035642.html
When a DNA Test Says You’re a Younger Man, Who Lives 5,000 Miles Away in the New York Times at https://www.nytimes.com/2019/12/07/us/dna-bone-marrow-transplant-crime-lab.html
Man discovers his DNA changed after bone marrow transplant in The Sun at https://www.thesun.co.uk/news/10515134/man-dna-changed-bone-marrow-transplant/
If I received a bone marrow or stem cell transplant, should I use AncestryDNA®? at https://www.ancestry.com/lp/bone-marrow-stem-cell-transplant-dna-test
You probably can find more articles by searching with any of today’s web search engines.