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Opening remarks for T2T media briefing

Eric Green, M.D., Ph.D. March 31, 2022

From the NHGRI Director

Good morning. Thank you, Sarah, for that wonderful introduction. 

I am absolutely delighted to be the moderator for today’s media briefing about the series of publications reporting the first complete, gapless sequence of a human genome, which has been generated by the Telomere-to-Telomere (T2T) consortium.

This is a remarkable achievement!

This consortium, which includes leading researchers at NHGRI; the University of California, Santa Cruz; and the University of Washington, Seattle, has given us — at long last — a complete view of the human DNA blueprint.

But, wait, you say?! Didn’t the Human Genome Project announce the same thing about 19 years ago?

Well, yes and no. In some ways, this press briefing and these publications might be considered the long-awaited closing ceremony (or perhaps encore) to that incredibly audacious project, which determined as much of the human genome sequence as was possible with the tools in hand at the time — about 92%. Back then we called it an essentially complete (or near-complete) human genome sequence.

Scientists inspired by that initial endeavor have now finished what I and other members of the Human Genome Project started.

And so we now have come full circle. And it turns out that this latest effort took almost twice as long to determine the last 8% of the human genome sequence as the Human Genome Project did for the first 92%!

That’s because that remaining 8% or so of the human genome is really messy stuff— mostly reflecting sections of the human genome that consist of long, repetitive stretches of letters that are difficult to read and difficult to put in the right place in the overall assembled sequence. Over the past two decades, all new technologies for sequencing DNA have emerged, among then methods that allow researchers to read much longer stretches of DNA at a time — from only about 500 bases back then to over 100,000 bases now — which allowed the T2T researchers to sequence and assemble the full length of the most difficult repeats.

And so missing piece by missing piece, the T2T team read and assembled these really rugged, repetitive bits around the centromeres, the telomeres and the various other random places around the genome.

I mean, talk about perfectionists! These scientists saw that this amazingly important puzzle was missing a few pieces and decided to take all the technological advancements of the last two decades — with a big dash of creativity and hardcore computer science (and a bunch of intellectual sweat) — to complete the picture.

This complete sequence now forms an unbroken thread that not only connects to the past work of the Human Genome Project but also points to future possibilities.

As importantly, the T2T consortium’s work critically underscores that not only does genomics achieve most with strong international and interdisciplinary teams working collaboratively towards a common goal, but that we can all function effectively in a single scientific network: academics and private industry, and scientists both within and outside the federal government. The proven success of such networks for pursuing big efforts in biology and medicine is another of the lasting legacies of the Human Genome Project.

I am proud to say that NHGRI played a fundamental role in the guidance and funding of this effort. This sequence would not be complete without the critical contributions of our Intramural Research Program and our Extramural Research Program, in addition to other staff that provided bioethics and policy expertise. And we would not be here if not for the talent and wisdom of our genomics grantee community. Many of those grantees have been with us for a long time.

With a complete human genome sequence now available, we realize that this milestone is but one destination. The T2T consortium’s work serves as a reminder that though the potentialities are limitless, there is much work to be done towards a future where the benefits of telomere-to-telomere genome sequencing are available and accessible to all. This accomplishment will also drive frank and meaningful conversations about health equity and access as well as how to continue building genomic resources that are free from bias and underrepresentation.

This will be a future where complete genome sequences tell us more about basic biology and evolutionary history than we thought possible. This will also be a future where these sequences deeply inform our conversations with healthcare providers, helping us made more knowledgeable decisions about our health and well-being.

And with that I will say, we are open for questions.

Last updated: March 31, 2022