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Celebrating that last eight percent…

Tomorrow, April 25, 2022, is National DNA Day here in the United States.

It’s a day to celebrate “the successful completion of the Human Genome Project in 2003 and the discovery of DNA’s double helix in 1953,”1 credited to Cambridge University scientists James D. Watson and Frances H.C. Crick.

Of course, neither of those events actually occurred on April 25th. Watson and Crick published their report about it on April 25, 1953, but had already announced their belief that they might have determined the double-helix structure of DNA earlier that year, and their lab director had announced it on April 23.2 The successful completion of the Human Genome Project was announced on April 14, 2003, by the National Human Genome Research Institute (NHGRI), the Department of Energy (DOE) and their partners in the International Human Genome Sequencing Consortium.3

And, of course, The Legal Genealogist sternly notes that there must be no mistake here — deserving credit as well is an English chemist and X-ray crystallographer named Rosalind Franklin, who did much of the early data modeling.4

As genealogists, we can all be thankful for the usual National DNA Day sales: check out MyHeritage DNA (ends tomorrow); Family Tree DNA (ends tomorrow); and LivingDNA (no expiration stated). There’s also a buy-one-get-10%-off-additional-kits sale at 23andMe.5

As people who adore the advance of science, we have even more to be thankful for this year.

DNA Day graphic

You see, that 2003 achievement — “the successful completion of the Human Genome Project” — wasn’t 100% complete. It was about 92% complete, with over 150,000 gaps of DNA left to be sequenced.

Now, here in 2022, it’s done.

That last eight per cent has been sequenced.

Just a little more than three weeks ago, NHGRI announced that the Telomere to Telomere (T2T) consortium had succeeded in the effort to publish “the first complete, gapless sequence of a human genome.”6

Now yeah I know. That sounds incredibly geeky. But that last no-longer-missing chunk is nothing to sneeze at. “That last 8% includes numerous genes and repetitive DNA and is comparable in size to an entire chromosome.”7

So what does this mean in the real world? Read what NHGRI had to say about it:

Analyses of the complete genome sequence will significantly add to our knowledge of chromosomes, including more accurate maps for five chromosome arms, which opens new lines of research. This helps answer basic biology questions about how chromosomes properly segregate and divide. The T2T consortium used the now-complete genome sequence as a reference to discover more than 2 million additional variants in the human genome. These studies provide more accurate information about the genomic variants within 622 medically relevant genes.

“Generating a truly complete human genome sequence represents an incredible scientific achievement, providing the first comprehensive view of our DNA blueprint,” said Eric Green, M.D., Ph.D., director of NHGRI. “This foundational information will strengthen the many ongoing efforts to understand all the functional nuances of the human genome, which in turn will empower genetic studies of human disease.”

The now-complete human genome sequence will be particularly valuable for studies that aim to establish comprehensive views of human genomic variation, or how people’s DNA differs. Such insights are vital for understanding the genetic contributions to certain diseases and for using genome sequence as a routine part of clinical care in the future.8

Yeah. Not so geeky now, is it?

In our lifetimes, maybe. Even for some of us old farts. Routine individualized genetic medical care.

That really is something to celebrate here on National DNA Day 2022.

Cite/link to this post: Judy G. Russell, “DNA Day 2022,” The Legal Genealogist ( : posted 24 Apr 2022).


  1. About DNA Day,” National Human Genome Research Institute, National Institutes of Health ( : accessed 24 Apr 2022).
  2. See generally Wikipedia (, “James Watson : Identifying the double helix,” rev. 22 Apr 2022.
  3. See ibid., “Human Genome Project,” rev. 18 Apr 2022.
  4. See ibid., “Rosalind Franklin,” rev. 17 Apr 2022. And see ibid., “James Watson : Identifying the double helix: Interactions with Rosalind Franklin and Raymond Gosling,” rev. 22 Apr 2022.
  5. Nope. Not at Ancestry right now. Check back in May around Mother’s Day and Memorial Day…
  6. See Prabarna Ganguly, Ph.D. and Rachael Zisk, “Researchers generate the first complete, gapless sequence of a human genome,” NHGRI News & Events, posted 31 Mar 2022 ( : accessed 24 Apr 2022).
  7. Ibid.
  8. Ibid.
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