What do a human, a rose, and a bacterium have in common?
Each one of these, along with every other living organism on Earth, contains the molecular instructions for life, called deoxyribonucleic acid or DNA.
Encoded within the DNA are the directions for traits as diverse as the colour of a person’s eyes, the scent of a rose, and the way in which bacteria infect a lung cell.
In other words, DNA codes our existence.
The 21st century is the golden age of DNA.
Indeed, the effect of DNA discovery on scientific and medical progress has been enormous. One significant area is Genetics.
Basically, Genetics is the branch of biology that deals with heredity, especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms.
These characteristics are determined by the expression of genes present in the DNA of offspring’s cells.
The convergence of next-generation sequencing and DNA has allowed scientists to make accurate predictions and discoveries about many diseases and how they can affect individuals based on their genetic makeup. In some cases, elements of disorders have never been noted before, and this advent of NGS has allowed for advanced diagnosis and also treatment.
DNA research encompasses an evolving area of progress and its relevance will abide to fuel new discoveries in the future.
What is DNA?
DNA or deoxyribonucleic acid is a long and complex molecule found inside chromosomes that stores all the genetic information a cell needs to undergo physiological processes necessary to build a functioning organism.
In order for this to happen, the DNA within the nucleus has to make a copy of itself so that each new cell will have a complete set of genetic instructions.
These instructions are passed down from parents to their children, one from mother and one from father. The combination of the genes we inherit as well as environmental factors will determine what we look like and who we are, therefore each human being is unique.
DNA is the “blueprint of life” and is considered as one of the building blocks of the body.
What is its structure?
DNA is shaped like a twisted ladder. Nucleotides are attached together to form two long strands that spiral to create a structure called a double helix.
Human DNA is compressed in the form of chromosomes. If we unfold these chromosomes, a DNA molecule looks like a double helix made of two strands twisted around each other.
These strands are interconnected by the nucleotides which are distributed in pairs.
Each single nucleotide is made up of a nitrogenous base, a five-carbon sugar and one phosphate group.
The assembly, in a formidable and fascinating complexity, holds all the information of a living, breathing organism.
What makes up DNA?
Overall, DNA is organized into 23 pairs of chromosomes.
The information is stored as a code made up of 4 chemical bases: adenine (A), guanine (G), cytosine (C), thymine (T).
Bases pair up with each other, always in the same way A with T, C with G to form units called “base pairs” which essentially means that if there is a set sequence of bases one side of the chain, the other side is automatically determined.
Each base pair is joined together by hydrogen bonds.
How was DNA discovered?
DNA was first observed by a German biochemist named Frederich Miescher in 1869.
However, for many years researchers did not look up at this molecule until 1953 that James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin figured out the structure of DNA.
Thanks to Rosalind Franklin’s x-ray photo 51, scientists James Watson and Francis Crick formally announced on April 25, 1953 the eminent discovery of DNA structure, following its publication on Nature magazine.
The article revolutionized the study of biology and medicine.
Watson and Crick’s words have cleared the way for huge strides in our understanding and have built the foundation for our knowledge on the DNA molecule.
In reality, that day, the modern era of biology began and prenatal screening is among the developments derived directly from it.
As a matter of fact, prenatal testing, mainly focused on trisomy 21 started around 1970 and went through several significant improvements.
From 2011, DNA sequencing methods have enable to analyse the cell-free DNA circulating in the expecting mother’s bloodstream from a standard blood draw.
These tests based on cell-free DNA sequencing can potentially reduce invasive diagnostic procedures.
Tranquility is Genoma’s most accurate Non-invasive cell-free fetal DNA screening for Trisomy disorders and sexual aneuploidies.
What is DNA sequencing?
Sequencing DNA is a technology that allows scientists to determine the orders of the four chemical bases (A, C, G and T) in a DNA molecule.
The sequence tells the kind of genetic information carried in a particular DNA segment.
Next generation sequencing (NGS) also referred as massively parallel sequencing means that millions of DNA strands can be sequenced at the same time, creating a massive pool of data.
The applications of next-generation sequencing technologies are vast, owing to their relatively low cost and large-scale high-throughput capacity.
Using these technologies, scientists have been able to rapidly sequence entire genomes of organisms, to discover genes involved in disease and to better understand genomic structure and diversity among species in general.
The Human Genome Project is one of the great feasts of exploration in History. This international scientific research project, completed in April 2003, has sequenced and mapped all of the genes, known as the genome.
For the first time, the ability to read nature’s complete genetic blueprint for building a living, breathing organism of which humans are an example of, has been achieved and consequently has impacted the fields of medicine, biotechnology and life sciences.
What is DNA testing?
Your DNA contains information about your genetic heritage and can eventually reveal whether you are at risk for certain disorders.
DNA tests or genetic screening tests are used for a variety of reasons, including to identify whether a person is a carrier of a genetic predisposition and therefore at risk for disease.
For instance, mutations in the BRCA1 and BRCA2 genes are known to be the most significant risk factors for breast and ovarian cancer.
Indeed, harmful variants in BRCA genes induce breast and/or ovarian cancer and can provoke an early onset, even before 30 years old.
Currently, the leading scientists advocate for BRCA1 and BRCA2 genetic screening for every woman from the age of 30 as a part of routine medical care.
Early detection of actionable mutations is essential for cancer prevention.
With a risk-free buccal swab for DNA collection, Serenity is Genoma’s new generation exclusive genetic screening test performed in Geneva’s laboratory that screens the entire coding regions of BRCA1 and BRCA2 genes and detects all variants.