# How accurate is DNA age testing? **URL:** \ **Category:** Factual Questions\ **Created:** [October 4, 2018, 7:03pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441 "2018-10-04T19:03:18Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Contemplation](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Contemplation](https://boards.straightdope.com/u/Contemplation)\ **Post date:** [October 4, 2018, 7:03pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/1 "2018-10-04T19:03:18Z")
A decade ago there was an article based on DNA testing the US used to determine the age of Dominican baseball players and to see if they lied about their age. Is a DNA test really accurate enough to tell the difference between a 15 year old, and an 18 year old? The teen-adult difference matters a lot in sports. ---
**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:** [October 4, 2018, 7:09pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/2 "2018-10-04T19:09:29Z")
Well, out of the two options for the tests, [they do _not_ seem to be Shinola](https://blogs.plos.org/dnascience/2018/07/12/telomere-testing-science-or-snake-oil/). ---
**Author:** ![Contemplation](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Contemplation](https://boards.straightdope.com/u/Contemplation)\ **Post date:** [October 4, 2018, 7:32pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/3 "2018-10-04T19:32:55Z")
> [@Darren\_Garrison](#): > > Well, out of the two options for the tests, [they do _not_ seem to be Shinola](https://blogs.plos.org/dnascience/2018/07/12/telomere-testing-science-or-snake-oil/). That is just one type of DNA testing. I doubt something that unreliable would be used to determine whether an athlete gets banned or not. ---
**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:** [October 4, 2018, 8:16pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/4 "2018-10-04T20:16:27Z")
> [@Contemplation](#): > > That is just one type of DNA testing. I doubt something that unreliable would be used to determine whether an athlete gets banned or not. It wouldn’t be the first time that officials fell for pseudo-scientific nonsense. [Here](https://www.ncbi.nlm.nih.gov/pubmed/28691915) is a study from last year about a new method–that is accurate to +/- 4 years. So still not Shinola. ---
**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:** [October 4, 2018, 8:20pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/5 "2018-10-04T20:20:44Z")
[And the real answer](https://www.nytimes.com/2009/07/22/sports/baseball/22dna.html): > [@](#): > > The DNA test does not reveal an age, but it can reveal whether the player is the son of his claimed parents. Players have been known to find families willing to lend a younger child’s birth certificate so that a player can appear younger. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [October 4, 2018, 8:26pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/6 "2018-10-04T20:26:58Z")
> [@Darren\_Garrison](#): > > The DNA test does not reveal an age, but it can reveal whether the player is the son of his claimed parents. Players have been known to find families willing to lend a younger child’s birth certificate so that a player can appear younger. It seems to me that a lent birth certificate would show the wrong parents so the claim would have to be that the child was adopted (or something similar) in which case a parental match would not be expected. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [October 4, 2018, 8:32pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/7 "2018-10-04T20:32:00Z")
> [@Contemplation](#): > > A decade ago there was an article based on DNA testing the US used to determine the age of Dominican baseball players and to see if they lied about their age. > > Is a DNA test really accurate enough to tell the difference between a 15 year old, and an 18 year old? The teen-adult difference matters a lot in sports. You might be confused with Horvath’s Epigenetic clock, which can predict how long you’ve got to live with remarkable accuracy (r = 0.96): > **[Epigenetic clock](https://en.wikipedia.org/wiki/Epigenetic_clock)** > > An epigenetic clock is a biochemical test that can be used to measure age. The test is based on DNA methylation levels, measuring the accumulation of methyl groups to one's DNA molecules. > The strong effects of age on DNA methylation levels have been known since the late 1960s. A vast literature describes sets of CpGs whose DNA methylation levels correlate with age. The first robust demonstration that DNA methylation levels in saliva could generate age predictors with an average accuracy of 5.2 y... ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [October 4, 2018, 10:55pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/8 "2018-10-04T22:55:34Z")
[https://www.nature.com/articles/d41586-018-06121-w](https://www.nature.com/articles/d41586-018-06121-w) > [@](#): > > Horvath has since refined the method. In July, he published a new clock that measured epigenetic marks at 391 DNA sites in different tissues. It was particularly accurate in buccal cells scraped from the inside of the cheek, which are easier to collect than blood samples. Testing these buccal cells from 53 people aged between 3.5 and 18 years, he found a **median error of just 1.03 years**. ---
**Author:** ![DinoR](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dinor/32/2821_2.png) [@DinoR](https://boards.straightdope.com/u/DinoR)\ **Post date:** [October 4, 2018, 11:29pm UTC](https://boards.straightdope.com/t/how-accurate-is-dna-age-testing/822441/9 "2018-10-04T23:29:51Z")
> [@OldGuy](#): > > It seems to me that a lent birth certificate would show the wrong parents so the claim would have to be that the child was adopted (or something similar) in which case a parental match would not be expected. Well there’s another answer if it’s just the father that doesn’t match the birth certificate. [One in 25 fathers is not biological parent - study](https://www.theguardian.com/society/2005/aug/11/childrensservices.uknews) It’s older as a cite. The story referenced study looked at studies where 1-30% of fathers listed on birth certificates aren’t the biological father. If they can at least show the DNA matches the mother on the birth certificate that’s a strong argument for a valid birthdate on the certificate. I’d hope any sports governing agency testing DNA would look at the consequences of how they manage the data with respect to claimed biological fathers.