# Consumer DNA testing - how do they communicate non-XX, non-XY status? **URL:** \ **Category:** Factual Questions\ **Created:** [December 27, 2020, 2:12pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022 "2020-12-27T14:12:05Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 27, 2020, 2:12pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/1 "2020-12-27T14:12:05Z")
Those home DNA tests sold for genealogical research – how do they handle communicating to people the fact that their chromosomes are neither XX nor XY, in the cases where that’s so? I think it’s about 1% of people who fall outside the two most common sex chromosomal makeup, the great majority of them unaware. Perhaps consumer DNA tests don’t actually detect this? I’ve never heard of anybody learning this through their test. There must be many thousands of customers for whom this would be the case. ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [December 27, 2020, 4:15pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/2 "2020-12-27T16:15:39Z")
23andMe covers this issue in an [FAQ page](https://customercare.23andme.com/hc/en-us/articles/360010964373-How-23andMe-Uses-Your-Self-Reported-Sex#I%20have%20a%20genetic%20condition%20that%20affects%20my%20sex%20chromosomes): > [@23andMe](#): > > The 23andMe Personal Genetic Service analyzes your DNA at specific points throughout your genome where single letters of the genetic sequence have been shown to differ among individuals. This process is called SNP genotyping, and is not well-suited for detecting most chromosomal abnormalities, such as Turner syndrome (45,X) and Klinefelter syndrome (47,XXY). > > The vast majority of 23andMe Carrier Status[\*](https://customercare.23andme.com/hc/en-us/articles/360010964373-How-23andMe-Uses-Your-Self-Reported-Sex#disclaimer) and Health Predisposition[\*](https://customercare.23andme.com/hc/en-us/articles/360010964373-How-23andMe-Uses-Your-Self-Reported-Sex#disclaimer) Reports are based solely on genes located in chromosomes 1-22 (not the sex chromosomes). Thus, these reports should not be impacted by any sex chromosome abnormality. > > However, our test does look at variants on the X chromosome for one of our Genetic Health Risk reports (G6PD Deficiency\*\*) as well as for our Ancestry Composition Report. If you have questions about how your genetic condition will impact these reports for you, please reach out to our [Customer Care team](https://customercare.23andme.com/hc/en-us/requests/new). So it seems that most of the non-standard sets of chromosomes (46 plus XX or 46 plus XY) would not show up in their test, as they’re not looking at the sex chromosomes. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 27, 2020, 8:20pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/3 "2020-12-27T20:20:57Z")
> [@Schnitte](#): > > So it seems […] So it does indeed. Hey, thank you for tracking that down for me! That’s very kind of you. I genuinely appreciate it! ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [December 27, 2020, 8:32pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/4 "2020-12-27T20:32:33Z")
Their tests could pick up the presence of two X chromosomes where only one is expected, if the subject happens to be heterozygous (two variants present) at one or more of the loci they test on X. So this could pick up undiagnosed Klinefelter, since the XXY phenotype is male. What they do with this information if it comes up - I have no idea. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [December 28, 2020, 4:58am UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/5 "2020-12-28T04:58:02Z")
For an analogy, these tests just do a key-word search on your DNA, they don’t read the whole text. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [December 30, 2020, 4:37am UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/6 "2020-12-30T04:37:55Z")
And now I’m thinking of this XKCD comic: > **[Coronavirus Genome](https://xkcd.com/2298/)** > > Spellcheck has been great, but whoever figures out how to get grammar check to work is guaranteed a Nobel. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 30, 2020, 2:25pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/7 "2020-12-30T14:25:43Z")
Is that really true about spellcheck? And how do you add a spelling to spellcheck as incorrect? I thought it simply underlined anything that was NOT in its list of spellings. This is one of those times I suspect myself of cluelessness but really can’t tell. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [December 30, 2020, 3:41pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/8 "2020-12-30T15:41:45Z")
> [@Napier](#): > > Is that really true about spellcheck? And how do you add a spelling to spellcheck as incorrect? I thought it simply underlined anything that was NOT in its list of spellings. [The “Explain XKCD” website on 2298: Coronavirus Genome](https://www.explainxkcd.com/wiki/index.php/2298:_Coronavirus_Genome) ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 31, 2020, 5:40pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/9 "2020-12-31T17:40:48Z")
> [@Napier](#): > > Is that really true about spellcheck? And how do you add a spelling to spellcheck as incorrect? I thought it simply underlined anything that was NOT in its list of spellings. It’ true that spellcheck just looks at a list of known strings and flags as red anything unknown. But if you add the current genetic sequence of letters to spellcheck as a known correct “word” and later find a sequence that’s _almost_ the same, it’ll be flagged as unknown to spellcheck and therefore you know it’s different from all your known sequences already saved as correct words. ---
**Author:** ![Cleophus](https://avatars.discourse-cdn.com/v4/letter/c/a88e57/32.png) [@Cleophus](https://boards.straightdope.com/u/Cleophus)\ **Post date:** [December 31, 2020, 5:49pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/10 "2020-12-31T17:49:42Z")
> [@Napier](#): > > Is that really true about spellcheck? And how do you add a spelling to spellcheck as incorrect? I thought it simply underlined anything that was NOT in its list of spellings. Is what true about spellcheck? That you can add custom words to it? Yes, of course. Do biologists use Word to analyze DNA sequences or use spell check to identify mutations? No, absolutely not, that is the joke. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 31, 2020, 7:32pm UTC](https://boards.straightdope.com/t/consumer-dna-testing-how-do-they-communicate-non-xx-non-xy-status/929022/11 "2020-12-31T19:32:21Z")
> [@Cleophus](#): > > Do biologists use Word to analyze DNA sequences or use spell check to identify mutations? No, absolutely not, that is the joke. That’s what I was asking about being true. It wasn’t clear to me that that was a joke. Thank you!