The missing DNA links

For the first time in history, a team of scientists has managed to decipher the entire sequence of a person's genome. This is a major milestone that will allow for unprecedented breakthroughs in medicine, especially in the treatment of diseases like cancer and Alzheimer's.

29 July 2021

We humans come with an instruction manual: our DNA, which, like an orchestra conductor, tells the cells what functions to perform and how to carry them out. The results of research throughout history have determined that each person has about 20,000 genes, which contain vital information and provide unique features such as eye color, blood type, height, and hair color, among many others. However, despite the accuracy of the research, 8% of the genome had yet to be deciphered, but that has now been achieved as was announced in early June, and that has scientists popping champagne corks.

Why is this important? Many diseases have a genetic origin, so knowing the complete human genomic code will improve existing therapies for a definitive cure. Additionally, this scientific finding will allow for earlier diagnosis, even before the first symptoms of a severe pathology appear.

  • For example, Alzheimer’s disease has a risk of occurring that is associated with several genes that are located on chromosomes 1, 14, 19 and 21. The same is true for Huntington’s disease, which also has a genetic basis related to a gene located on chromosome 4. Now, thanks to having the complete DNA code, understanding why these genes are expressed and how they cause these diseases will make it possible to find an appropriate treatment.
  • The case of actress Angelina Jolie is a good example for understanding how DNA sequencing makes it is possible to predict whether a woman is likely to suffer from a particular type of breast or ovarian cancer.
  • It is also the case that when the genetic code is incomplete or contains errors it can lead to genetic diseases, which is why this discovery is so important. Having detailed genetic information and knowing how genes are arranged allows us to know how the human body works and how certain diseases are transmitted.

How was this achieved? The complete DNA sequencing was announced by the Telomere-to-Telomere Consortium (T2T Consortium), a research project involving the collaboration of universities and technology companies from several countries. Among those involved in this discovery are California-based Pacific Biosciences (PacBio) and UK-based Oxford Nanopore.

  • The T2T Consortium has more than 100 researchers in its ranks. The Consortium is currently led by Karen Miga of the University of California and Adam Phillippy of the National Human Genome Research Institute in Maryland.

A bit of background In 1953, researchers Watson and Crick described the structure of DNA as a double helix, a finding for which they received the Nobel Prize in conjunction with Maurice Wilkins. Genetic research continued moving ahead at an ever-increasing pace, culminating with the complete sequencing of the human genome. In 1990 the Human Genome Project was founded.

  • The Project was spearheaded by the United States, the United Kingdom, Japan, France, Germany and China, and began sequencing the genetic map of our Homo Sapiens
  • In April 2000, the Project’s first draft was published. Then, in 2001, the journals Nature and Science published the then definitive sequence of the human genome, with a 99.9% confidence interval.

What’s ahead? The heretofore unknown 8% of the DNA sequence has been linked to many health problems, from ALS to cancer and autism. By completing the sequence, many scientists believe that these conditions can be better studied and treated with what is known as ‘personalized medicine.’

  • “Having sequenced the entire human genome will help us to understand the mechanisms at the origin of a given pathology, as well as to develop more direct and precise drugs against diseases so that they are less prevalent,” explains Dr. Jorge Dotto, a medical geneticist with broad experience in the United States and Europe.
  • “With a simple saliva sample, we will be able to determine each person’s genetic predisposition to cancer, adjust our follow-up much more precisely and efficiently, and offer more individualized treatments with what has come to be called `personalized medicine,” explains Luciano Cerrato, an oncologist at Ruber Internacional.