What is Respiragene™?
Respiragene™ is an innovative and powerful genetic test that assesses your inherent risk of developing lung cancer, whether you are a current or former smoker. The Respiragene™ test will identify whether you are at moderate risk, high risk, or very high risk of developing lung cancer at some point in your life, compared to other smokers. Armed with this information, you can take steps to lower your risk of disease such as quitting smoking. You and your doctor may also use this personalized information to take additional steps to monitor and to protect your health.
If you are a current or former smoker, you are at significantly greater risk than non-smokers for developing a range of diseases, including lung cancer. According to the US Centers for Disease Control, 10% to 15% of long-term smokers will get lung cancer. The likelihood of developing lung cancer increases steeply after long-term smokers turn 50. On average, smokers are 20 to 30 times more likely to contract lung cancer than life-long non-smokers.
Among smokers and ex-smokers, many individuals are at higher than average risk of developing lung cancer due to their genetic make-up. Respiragene™ distinguishes between smokers and ex-smokers at "moderate risk", "high risk" and "very high risk". Those at "moderate", or average, risk have an estimated 10% lifetime risk for lung cancer, meaning about one in 10 of them will develop lung cancer. A high risk means a person is four times more likely to get lung cancer than an average smoker. A very high risk result means that a person has 10 times the risk of an average smoker.
The power of genetic testing
Major advances have occurred recently in medical diagnostic testing, driven by an increased understanding of human genetics. New technologies seek to use patient DNA to detect individuals at elevated risk for various cancers. Some tests help doctors prescribe the most effective therapeutics for individuals, based on their genetic profiles. Others are predictive, measuring susceptibility to inherited diseases and illnesses where environment or behavior can trigger the onset of disease in those who are most vulnerable.
Respiragene™ is one of these "predictive" tests. It detects the presence or absence of specific targeted genetic markers associated with resistance or susceptibility to lung cancer to identify individuals at highest risk of developing lung cancer, compared with other smokers.
What are DNA and Genes?
All genetic tests involve the assessment of DNA (deoxyribonucleic acid), which contains the code used in the growth and function of all living organisms. The main function of DNA is the storage of information; the instructions contained within DNA are used to construct other components of cells, which are the fundamental working units of every living organism. The sections of DNA that carry this ‘genetic' information are called genes.
Within cells, DNA is organized into structures called chromosomes. Humans have a total of 46 chromosomes, matched in two pairs of 23 chromosomes each. The set of chromosomes in a cell make up its genome, and the complete set of this information in an organism is called its genotype. Chromosomes are comprised of physically separate molecules of DNA that range in length from about 50 million to 250 million base pairs of cross-linked, repeating units called nucleotides. Genes are located at specific positions on particular chromosomes that represent the fundamental physical and functional units of heredity in each of us. The human genome is estimated to contain some 25,000 genes. However, genes comprise only about 2% of the human genome; the remainder consists of non-coding regions, whose functions may include providing chromosomal structural integrity and regulating the actions of the genes.
The DNA double helix is made up of a series of one of four "bases" arranged sequentially on each parallel strand. The four bases found in all DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T) and each type of base on one strand forms a bond with just one type of base on the other, opposite strand. This is known as complementary base pairing, with A only bonding with T, and C only with G. As a result of this complementary pairing, the DNA sequence is duplicated on the opposite strand of DNA, which is vital for replication.
What are SNPs?
Within each gene there are many mutations or variations. Single nucleotide polymorphisms, or SNPs (pronounced ‘snips'), are one of the most common variations and account for many of the differences between people, particularly those affecting health and disease. A SNP occurs when a single nucleotide - A, T, C, or G - in a gene differs in sequence position between members of a species (or between paired chromosomes in an individual). Of the millions of SNPs in the human genome, most have no impact at all on the human body. But some specific SNPs have been linked to the development of disease and their presence provides an indication of a person's susceptibility to those diseases. The SNPs themselves do not necessarily cause these diseases, but act as 'biological markers' that can be assessed and used in combination with other environmental factors to determine a person's susceptibility to a particular disease. Respiragene™ measures SNPs which are related to susceptibility to lung cancer.