I used to upload DNA tests to some sites – FamilyTree DNA (FTDNA), MyHeritageDNA, and LivingDNA. One thing I noticed is the problem with going that route – ISOGG Autosomal SNP Comparison Chart – DNA Saturdays December 26, 2020. Specifically, the ISOGG Autosomal SNP Comparison Chart: https://isogg.org/wiki/Autosomal_SNP_comparison_chart. The wide variation in matching SNPs can be very large.
I saw this SNP comparison several years back and decided to wait until the various DNA tests were at a good sale price and buy the tests on sale. I removed the transferred tests to avoid duplicates. I know there is a way to combine each test into a super-kit. I have no plans at doing that for now, but may change my mind later.
I found testing directly is the best way to get an apples to apples comparison. I did the same thing with 23andMe’s v5 chip last year. I previously tested the v3 chip, but noticed the shared SNP comparison was over 300K SNPs fewer between v3 and v5 chips. They kept my v3 chip results so if I am comparing to other v3 chip testers, I share over 930K SNPs in common. For v5 chip sets, I am comparing against over 612K SNPs in common.
There are several things that can impact DNA tests. If you receive a bone marrow transplant or provide someone a bone marrow transplant, you would match each other as the bone marrow transplant would replace the person’s DNA receiving it. Chemotherapy can temporarily affect DNA tests. Suggestion is to wait until the blood cells return to normal levels in those situations. It’s rare that blood transfusions can affect the test although if you received a blood transfusion, best to wait a bit as it may affect the DNA test.
Previous DNA Saturdays posts: https://upsdownsfamilyhistory.wordpress.com/tag/DNA-Saturdays/