Dave- I know whereof I speak and I know that I am not confused but it sounds as though you may be. 23andme tests all chromosomes including X and Y (if pertinent--meaning only males have the Y chromosome). Why do you think they call it 23 and me...this refers to the 23 chromosomes -- which includes X (and Y if applicable). 23andme tests SNPs. When I examine my results for all chromosomes against those of potential cousins with whom I share data I can view the exact position of the matching segments on any of the chromosomes. I'm not sure what you mean by "my-DNA" testing. Pehaps you mean mtDNA? mtDNA testing is outside the 23 chromosomes and comes from the egg (which is why ALL children regardless of sex can be tested for mtDNA and is also why only females pass it along to their children). https://www.23andme.com/howitworks/ Joan In a message dated 5/19/2012 9:20:05 P.M. Eastern Daylight Time, odinaz@comcast.net writes: Joan, I am sorry but I am not an expert on the testing methods that are used by 23andme as well as their test loci, etc. But I can give you some feedback on the state of testing by most other current sites. I know of none of them using any loci located on the X or Y ("sex") chromosomes for AUTOSOMAL testing, so I am not going to comment on your "Find" beyond stating that it surprises me that 23andme does use those chromosome in their autosomal testing, IF, in fact, you are correct in your statements. Autosomal testing is NOT the same as Y-DNA testing. It is also not the same as my-DNA testing. Perhaps you have them confused? I don't know, but assuming what you are saying is correct, I would say that you have some fairly interesting miracles going on there that someone might want to study. Dave