Imagine a world in which scientists could analyze a sample of your DNA- taken, perhaps, from a simple swab inside your cheek- and know if you have a predisposition to heart disease or breast cancer, and explain what steps you could take to minimize the risk
That world is already here, and its benefits are becoming more accessible all the time.
This is Individual Genome Profiling.
Individual Genomic Profiing is the branch of genomics concerned with the sequencing, analysis and interpretation of the genome of an individual. The genotyping stage employs different techniques, including single-nucleotide polymorphism (SNP) analysis chips, or partial or full genome sequencing. Once the genotypes are known, the individual's variations can be compared with the published literature to determine likelihood of trait expression, ancestry inference and disease risk.
It all began about 17 years ago with the Human Genome Project, a 13-year international effort to determine the sequence of the 3 billion "letters" in a human being's DNA.
The $3 billion project, led by the U.S. Department of Energy and the National Institutes of Health, began in 1990 and was completed on April 14, 2003. Since then, scientists have achieved many important milestones in using genomic discoveries to advance medical knowledge.
Sequencing technology has vastly improved in recent years. Sequencing the first human genome cost about $1 billion and took 13 years to complete; and today the cost of sequencing a human genome is dropping rapidly, due to the continual development of new, faster, cheaper DNA sequencing technologies such as "next-generation DNA sequencing".
The National Human Genome Research Institute, an arm of the U.S. National Institutes of Health, has reported that the cost to sequence a whole human-sized genome has dropped from about $14 million in 2006 to below $1,500 by late 2015.
The tests available include the hugely popular 23 and Me saliva based test – which is named for the 23 pairs of chromosomes that make up human DNA – that estimates each individual’s predisposition to more than 90 traits and conditions ranging from baldness to blindness.
A less well known test is produced by My Gene Diet, which provides a gene analysis suggesting the best diet, effective exercise routine, and most successful weight management plan.
Probing Further;
But just knowing the sequence would be meaningless without a way to interpret it. So researchers found ways to study the genome’s function, by sequencing the genomes of 135 other organisms and surveying the global variation among human genomes.
Researchers compared the genome sequences of other animals, such as chimpanzees and platypuses, as well as other eurkaryotic organisms (those whose cells have a nucleus), such as yeast and flat worms. From this comparison, scientists could identify stretches of DNA that have remained largely unchanged over the course of evolution. Five to 8 percent of the human genome has been unchanged for thousands of years.
One surprising finding that was discovered is how little of the human genome (only 1.5 percent) actually encodes proteins, the molecular building blocks that perform most of the critical functions inside cells.
To probe this mystery, more than 400 researchers from 32 labs worldwide created the ENCyclopedia Of DNA Elements (ENCODE) consortium and they have published many important findings about how the human genome functions. These include locations in the genome that may be genetic "switches" to turn genes on and off, as well as demonstrating that more than 80 percent of the genome that was once called "junk DNA" actually does serve a function.
Other research has focused on measuring the variation among human genomes. Preliminary studies during the Human Genome Project indicated that human genomes differ by just one-tenth of a percent. This indicates we are nine-tenths identical clones and we differ on the basis of a one-tenth individual distinction on the subject of our genes.
So,Investigating the limited variation that does exist is key to understanding human health and disease.
• A catalyst for exploring different treatment options
Genetic screening may reveal that a person carries a certain gene that puts them at an increased risk of developing a disease. While this may initially seem like more of a negative than a positive, this important information enables individuals to seek out additional diagnostic testing from a medical institution, and explore early treatment options that could save their life.
By knowing which genes predispose people to particular conditions, doctors will be able to predict which people are likely to suffer from a particular disease and offer a preventive course of action, which may involve medical treatment or lifestyle changes. Furthermore, cures could be found for genetic diseases like cystic fibrosis or sickle cell anaemia.
Test results can also inspire positive lifestyle changes that help to ward off disease. In fact, a test result could be the catalyst that inspires someone to cut out soda and refined sugar and increase their daily exercise. Cultivating healthy habits is always a step in the right direction!
• Starting A Family
Test results may also help couples make important decisions about whether or not to expand their family. If test results indicate that there is a low risk of passing on a genetic condition, this may give couples incredible peace of mind if they are considering having children.
It also helps in diagnosing any genetic disorders from early on, so that the treatment can be supplied.
• Improved Medicine
Personalized medicines can be developed based on the way our individual bodies react to the disease and the treatments, which will be more effective because the medicines will be tailored for our specific medical needs.
Such approaches promise the advent of precision medicine and even personalized medicine, in which drugs and drug combinations are optimized for narrow subsets of patients or even for each individual's unique genetic makeup.
Pharmacogenomics: Customized Medicine For Patients
• Devaluing Some Lives
But a little knowledge is a dangerous thing, ethicists say, and people who are considering finding out what their genome says need to think seriously about what that information will tell them, and how they and other people might use it.
For example, having such an information, expectant mothers might abort their child if they find any genetic flaw in the child. The genetic tests can’t be used for determining which life should be given a chance to live and which shouldn’t as isn’t necessary that someone carrying problematic genes will develop problems at a later stage.
“ One of the first things we have to be careful about is the idea that we are our DNA, it's a kind of genetic reductionism. But we are so much more than that.” says Jesuit Father Kevin T. FitzGerald.
Father FitzGerald is a founding member of Do No Harm, a member of the ethics committee for the March of Dimes, and a member of the American Association for the Advancement of Science Program of Dialogue on Science, Ethics, and Religion.
The important thing, he said, is to remember that all human lives have value, that we all have genetic flaws, and the best way to use genetic information is to help each person live the best life he or she can.
“There is no perfect genome, and there are going to be some significant surprises, some things we didn't know about ourselves,” Father FitzGerald said. “ Everybody has genetic flaws. It just depends on how they manifest in the person's life.”
One big fear, he said, is that genetic tests will increasingly be used to determine whose life is worth living at all.
“They now have the ability to sequence the genome of a fetus while it is in the womb of the mother, by just drawing blood from the mum” Father FitzGerald said. “If you are looking for something wrong in the genome, of course you'll find it.”
• A Negative Result
Additionally, it is not always clear what a person should or should not do once they receive their genetic test results, as often doctors do not know the most effective ways to prevent certain diseases, conditions or cancers.
For example, let’s say your most recent genetic test indicates you may be at a slightly higher risk of developing Amyotrophic Lateral Sclerosis, or ALS.
ALS is a specific disorder that involves the death of neurons, resulting in stiff muscles, muscle twitching, and gradual weakening due to muscles decreasing in size. This eventually results in difficulty speaking, swallowing, and breathing. Doctors estimate that five to ten percent of ALS cases are genetically inherited, however, tragically, there is no known cure for ALS. Research is ongoing but so far, scientists aren’t sure why the disease progresses more quickly in some patients than in others. If a test were to indicate that you might be in a higher risk category – whether or not you eventually developed the disease – you might understandably be unnerved and exceptionally paranoid about your health.
This stress could negatively impact other aspects of your life as well, leading to anxiety issues, stomach ulcers, etc.
• Genetic Discrimination
Genetic discrimination occurs when people treat others (or are treated) differently because they have or are perceived to have a gene mutation(s) that causes or increases the risk of an inherited disorder.
Everyone should care about the potential for genetic discrimination. Every person has dozens of DNA differences that could increase or decrease his or her chance of getting a disease such as diabetes, heart disease, cancer or Alzheimer's disease. It's important to remember that these DNA differences don't always mean someone will develop a disease, just that the risk to get the disease may be greater.
More and more tests are being developed to find DNA differences that affect our health. Called genetic tests, these tests will become a routine part of health care in the future. Health care providers will use information about each person's DNA to develop more individualized ways of detecting, treating and preventing disease. But unless this DNA information is protected, it could be used to discriminate against people.
References
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