Advertisement
Health

Johns Hopkins scientists join others to complete the human genome, expanding potential for better health care

Two decades after a group of scientists released a first draft of the human genome, a research consortium said Thursday that it has completed the genetic map, opening vast new opportunities to understand the makeup of the human body and improve people’s health.

About 100 government and academic scientists, including a team at the Johns Hopkins University in Baltimore, worked on this final part of the Human Genome Project, adding the last and most confounding 8% of genes missing from the blueprint for the human species.

Advertisement

They called it a massive undertaking that deployed far more advanced technology than was available 20 years ago.

“Eight percent feels at first glance like a small number,” said Michael Schatz, a consortium member and Johns Hopkins professor of computer science and biology. “But that’s the size of Africa; a whole continent was missing.

Advertisement

“We found more than a million additional genetic variants,” he said, “and each variant is associated with a specific disease.”

Gene sequencing has been used in the lab for years to understand broadly how traits and diseases develop — think about how the BRCA gene mutations make a woman more likely to have breast and ovarian cancer. In some cases the information has allowed scientists to develop new therapies and led doctors to tailor treatments to individuals.

With the new map and all the information it offers, such opportunities could expand exponentially, provided all the world’s labs adopt it, Schatz said.

The latest effort involved about 30 institutions that added or corrected more than 200 million DNA base pairs, increasing the number in the human genome to 3.05 billion. Those base pairs, made of chemical copies of genetic material bound together, form about 25,000 distinct genes.

The researchers, including Schatz, discussed the finding in a news conference Thursday with others from the National Institutes of Health’s National Human Genome Research Institute, the University of Washington and the University of California, Santa Cruz.

After pushing their research through the coronavirus pandemic, sharing information on the Slack messaging and Zoom meeting apps, the group published six main papers Thursday in the journal Science. The group is formally called the Telomere to Telomere (T2T) consortium. A telomere is the end of a chromosome, made up of sequences of DNA.

The work cost in the millions of dollars, but it was a far cry from the billions used to create the draft, said Adam Phillippy, consortium co-chair and head of the National Human Genome Research Institute’s Genome Informatics Section.

The cost and complexity mean it’s not yet common for people to have their genes mapped out, but the new findings and advancements in technology could make it far cheaper and more common for doctors to go looking for genetic defects in their patients that have immediate implications or effects down the line, he said.

Advertisement

Patients can now have their personal genome mapped and analyzed for several thousand dollars, depending on the specific needs, and it’s not typically covered by insurance.

“In 10 years, for less than $1,000, you may be able to go into a physician’s office and map your genome,” Phillippy said.

The newly discovered information will make those assessments more accurate, said Evan Eichler, co-chair of the consortium and a professor of genome sciences at the University of Washington.

The data also helps explain how humans have evolved and adapted, Eichler said, and explain how humans differ from other species.

“Half the genes that make our bigger brains come from these regions that were absent in the original genome,” he said.

That first draft was created first through competition and then cooperation between NIH and Rockville-based Celera Genomics, which abandoned plans to commercialize genomic data.

Advertisement

The new map was not based on one particular person, but a cell line derived from humans, and scientists say they hope to continue work to better understand different populations.

They also said fixes in the new genomic map will help researchers trying to understand the basics of disease development and progression, the aging process and other human traits because they will have more and better information.

Schatz, for example, said his lab already has begun investigating the genes associated with some cancers and it plans to begin a project looking into pediatric cancers based on the new information.

“We were looking at the high rates of cancer in some families and this will shed light on the genetic contributions,” he said. “In the pediatric cancer work starting tomorrow, in the same spirit, we’re sequencing data collected from about 1,000 individuals across a few hundred families, and in some cases we’ll be able to identify major genetic changes.”

The Morning Sun

The Morning Sun

Daily

Get your morning news in your e-mail inbox. Get all the top news and sports from the baltimoresun.com.

Other scientists are looking into genes associated with autism spectrum disorders and other diseases and conditions. There already are a lot of genes linked to specific diseases, but now researchers may find new, and possibly more meaningful combinations that lead to a small or large jump in a person’s risk of getting sick.

Schatz said some of the most common genetic testing already available to consumers is through genealogy websites that trace a person’s roots. They look at common variants to get a good idea where people’s forebears came from, sometimes just the continent, but sometimes more specifically the country or even the village.

Advertisement

He said the companies also are able to tell people about their risk for different diseases, with BRCA being the “most famous example, but there are a few thousand variants for different diseases.” He said sometimes there is an intervention such as changing your diet or more extreme measures such as mastectomies.

Specific genetically linked treatments are beginning to trickle out, he said, but developing more is the goal.

The new map is particularly gratifying to Schatz, who was inspired by the original Human Genome Project to switch careers from cybersecurity to genomics in the early 2000s.

“I always believed this could be done,” he said. “But I don’t think anyone really knew when it could be done and what it would really take. I thought it was going to take many more years. It really was a surprise to me how quickly we could get through it.

“This is something that’s been a pursuit of mine for 20 years. So, it is incredibly satisfying to see it come together.”


Advertisement