A recent article in the journal Nature describes the first draft of human genome analysis and sequencing published in 2001 by the Human Genome Project international consortium. The consortium included hundreds of researchers at twenty centers in six countries.
The human genome holds a vast amount of information about medicine, evolution, human development, and physiology.
The draft sequence includes over ninety percent of the human genome. The genome is the entire set of DNA and its genes.
Life Before the Draft
Prior to the creation of the draft genome, information concerning the genomic location and sequence of mutated genes was worked out by “cloning”. Not only did this process take years, but only a few laboratories could perform cloning.
Now, with the publishing of the First Draft, many people can receive their urgently needed diagnosis in a few hours and with unparalleled precision.
The Purpose of Sequencing a Genome
The first and foremost reason to sequence a person’s genome is that genomic sequencing offers information that may identify genetic variants that may lead to a disease. It also provides information about issues that increase the risk of a disease developing in the future. This is possible even if a person is not exhibiting symptoms (asymptomatic).
Note that variants are differences in a person’s DNA sequence. These differences affect a person’s individuality and the manner in which the body functions. The variants in genes might result in a gene that produces a protein that cannot function or a gene that cannot even produce a protein.
Is the Glass Half Full or Half Empty
The first draft of the human genome was published with much fanfare. It was expected to have a major impact on the medical community. The expectations were that medicine would become predictive, preventive, and personalized.
To those who did not see these transformations and who focused on common diseases such as coronary artery disease or diabetes, it was a major disappointment.
But for those who focused on Mendelian diseases such as sickle cell anemia, muscular dystrophy, cystic fibrosis, or thalassemia, it was life-changing.
These diseases are the result of mutations in a single gene. The list includes hereditary cancers and certain types of developmental delay.
One of the offshoots of this technology is that Mendelian diseases exhibiting a genetic cause rose from 1,257 as of 2001 to 4,377 today.
And Now Next-generation Sequencing
Combining the draft genome and a technology called next-generation sequencing caused scientists to celebrate the new and sensational combination by calling it a veritable game-changer. Researchers were now able to identify variants within the genome more rapidly.
The personalization aspect of disease management comes into play because now there are therapies available for disease-causing variants such as a gene that causes cystic fibrosis. This is just the beginning.
In summary, the draft does not link genes directly to a disease, but it is revolutionary in that it provides the elements that are necessary for diagnosis.
The goal is to expand the model and target lethal or severe recessive Mendelian disease genes. This goal is attainable and backed by publicly funded initiatives and the private sector.