The human genome is completed with key data for the early detection of diseases

The milestone comes from the Telomere to Telomere Consortium (T2T), which already in 2022 described the first complete human genome, after deciphering the 8% of human DNA that remained to be sequenced.

The work is published this Thursday in a special 12-article article on genomic advances in the journals Cell and Cell Genomics. They also report on the sequencing and analysis of the genome of 8 other vertebrate species: the macaque, the marmoset, the zebra finch, the rat, the vole, the horse, the donkey and the giraffe, which will offer important answers for science.

DNA sequencing makes up the human genome and is key to understanding the genes, which make the proteins that allow life. This genetic information constitutes a key to detecting and curing diseases, and advancing so-called personalized or precision medicine.

What the T2T Consortium presents today is the complete genome of a living donor, with the complete sets of chromosomes from each parent: the missing piece of the puzzle.

With “almost perfect” precision, because nothing is perfect in science, each chromosome spans ‘telomere to telomere’ and reveals 15% more of the genome known so far, including previously inaccessible portions that are relevant to cancer research or neurological disorders, among others.

The team has added more than 900 million DNA letters that were not included in previous benchmarks, including both sex chromosomes and areas with genes known to affect disease risk.

It is the “most complete and highest quality sequence of the human genome ever built, and will be a boost to make personalized genomics a common practice in health care,” announce researchers from Johns Hopkins University, the National Human Genome Research Institute and the National Institute of Standards and Technology, all in the United States.

“Our finding implies that in a short period of time it will be common to sequence a person’s entire genome. What will the future of medicine look like when a newborn’s entire genome can be generated, attached to their medical record, and used to guide precision medicine throughout their entire life?” asks one of the authors, Adam Phillippy, a researcher at Johns Hopkins University.

“The first T2T project was like putting together a huge puzzle. This time, we had pieces of two similar puzzles, one from the mother and one from the father, all mixed together in the same box. It was a more difficult computational challenge, but we have solved it,” adds Phillippy.

The researcher emphasizes, in a statement, that his results will improve the diagnosis of rare genetic diseases, especially in children: “This type of genetic analysis is already carried out today, but with less precision: in more than half of the cases, doctors may not be able to determine the genetic cause,” he explains.

In the longer term, The team hopes this new benchmark will make it easier for doctors to predict any patient’s disease risk.

Mutations in the BRCA1 and BRCA2 genes are currently used to predict the risk of breast cancer, for example, but complete genomes could improve the prediction of the risk of other types of cancer, heart disease, immune or neurological disorders.

“This, together with the genomes of many other non-human species, will allow us to train genomic models based on artificial intelligence to more accurately diagnose rare genetic diseases and guide personalized medical care,” concludes the researcher.

The authors recall that the total cost of the Human Genome Project, which concluded in 2003, was about $5 billion at current exchange rates. A more complete and accurate result of a person’s genome can now be obtained for about $5,000, which is a million-fold reduction.

For their part, animal reference genomes, such as those presented today, help researchers understand how the human body works and what makes it unique and different.

To study complex diseases like Alzheimer’s, scientists and doctors analyze, for example, how genes change and fail in other species, such as the small marmoset monkeys of South America, whose complete genome is also described today.