In the next few years, healthcare will undergo rapid changes. Technological advances in genomic sequencing will transform the way we interact with doctors and the medical industry. The opportunities for improving our health are incalculable, but as with any technologies there are risks of abuse and misuse. The news media is full of stories about DNA, genes and genomics, but for those who have never studied these topics it can get a bit confusing. In order to make informed decisions, consumers should understand the underlying concepts and why they are so important.
Every form of life on the planet is made of units called cells. You have about 10 trillion of them. In each of your cells there are structures called chromosomes that are made from millions of molecules joined together to form a macromolecule called deoxyribonucleic acid, or DNA. DNA is structured as a double helix; think of a rubber ladder that has been twisted, with the rungs made up of pairs of molecules called bases. There are only four bases, each known by its initial A, C, G, or T. We inherit 23 chromosomes from each parent. The largest chromosome has about 249 million rungs, and all 46 chromosomes together have about 6 billion rungs.
The function of chromosomal DNA is to provide the patterns required for our cells to produce the building blocks of life; very complex macromolecules called proteins. Proteins are made of thousands of smaller molecules called amino acids. When triggered by specific chemicals, sections of the chromosomes unwind and complex cellular machinery reads each strand like a ticker tape. The distinct pattern of As, Cs, Gs and Ts will tell the machinery in what order to assemble the amino acids into proteins.
A section of DNA that codes for a specific protein is called a gene, and you have about 25,000 genes. With a few exceptions, every cell in your body has the same genes, but only a subset of them are expressed in each type of cell. This is what makes a brain cell different from a bone cell or skin cell. Imagine a cookbook with 25,000 recipes. Every cell in the body has the same cookbook, but for each type of cell, a certain subset of recipes is produced.
The proteins that make us determine who we are. The essential differences between a jellyfish, a palm tree, and your high school English teacher are the types and arrangements of proteins from which they are made. Each species has a different cookbook, but closely related species have many of the same recipes. Differences within and between species can arise because of different proteins, or the same proteins arranged in different ways.
Since we inherit our genes from our parents, we are made of combinations of their proteins, which in turn will give us combinations of their characteristics, such as physical appearance and susceptibility to certain diseases. Except for identical siblings, a person’s DNA is unique to them and it can be extracted from blood, hair or even saliva, which is why it can be used as crime scene evidence. However, we must remember that over 99.9% of DNA is common to all human beings. The slight variations mean the difference between Scarlett Johansson and Usain Bolt.
Sometimes the DNA is not copied perfectly and we get genes that are mutated, meaning that they do not produce the normal protein. This can result in something as benign as a slight change in height, or a life-threatening disease such as Cystic Fibrosis. We currently know which traits are determined by just a few thousand of our genes, but are working to determine what the rest of our genes do.
Your full collection of genes is called your genome. Genomics is the study of genes and their functions, and genomic sequencing refers to the reading of a genome to determine the pattern of genes. The Human Genome Project began in 1990 with the task of mapping the first complete human genome. It was completed in 2003 at a cost of about $2.7 billion. Since then, the cost has dropped dramatically and now a full genome can be sequenced in less than a day for a thousand dollars. It is expected that within the next decade this could drop to as little as a penny.
There are many types of information we can learn from our genomes. Since genes are passed down from parents, we can use genetic information to verify parentage and to trace our ancestry, often to specific parts of the world. Ancestry.com has created a business of performing genetic testing and generating reports that tell you your ancestral roots, and maybe even that you are related to a famous historic figure.
Perhaps the most valuable use of genomic information is the identification of genes that cause disease or increased susceptibility to disease. By comparing genomes from people whose characteristics are known, researchers can find common genes that may be responsible for specific traits. 23andMe.com is a company that will analyze your DNA and identify a subset of known genetic markers for various conditions and susceptibilities to diseases. Many hospitals now have their own genome sequencing machines that can be used to study patients’ genomes.
Our genomes can also tell us which drugs may be most effective or cause the fewest side effects. Researchers are compiling databases of the relationships between genes and drugs, and one major Canadian pharmacy chain is already in negotiations with a company with plans to provide this service to patients.
Genomics will be most effective when large numbers of patients’ genomes are pooled and analyzed. There is a rush among many diverse research groups, both public and private, to gather genomic data for analysis which will doubtless lead to new drugs and potentially billions of dollars in profit.
If patients are having their genomes sequenced under the supervision of their doctors and made part of their medical records, then the genomic data fall under the same jurisdiction and protection as regular medical data. However, in cases where patients are sending their DNA to commercial enterprises, the same rules do not apply.
For example, in July 2015, Ancestry.com announced an agreement to share its customers’ data with Calico, a company owned by Alphabet (which also owns Google), for the purposes of research into the genetic causes of human longevity. While customers of Ancestry were given the option to opt out of the research, some found the process confusing, and have accused Ancestry of misleading them. I tried to navigate the web of privacy policies and statements on the Ancestry website but admittedly gave up after about 20 minutes, having found no specific mention of the Calico agreement or medical research, only vague references to data being shared with “third parties”.
Similarly, 23andMe is selling customers’ data to multiple companies for research, which may not have been the customers’ original intent. Other than the reports that were part of their original purchase agreements, customers are in no way compensated for the use of their data for research. This means that customers are literally paying companies to take their DNA and profit from its use.
In the next few years as genome sequencing becomes cheaper and cheaper, it will also become increasingly common. Sequencing a newborn’s genome at birth will become as routine as checking for blood type. We may have multiple versions of our genomes analyzed by different parties for different reasons. We may be tested for a specific gene, and when later research leads to the discoveries of the functions of more genes, those who possess our DNA may learn more about us than we know about ourselves, with no obligation, and perhaps no method, to inform us.
Although many jurisdictions have laws forbidding genetic discrimination by insurance companies and employers, it is easy to imagine scenarios where DNA is given voluntarily in return for some reward. For example, a health insurance company can offer to reduce rates if you voluntarily submit your DNA. Suppose a couple decides that they will each submit their DNA for reduced insurance rates. Since the insurance company now has the DNA of both parents, it can also know many traits of the children, even though the children have not submitted any DNA nor agreed to any testing.
Even medical testing has the potential to cause conflicts between family members. With diseases such as Alzheimer’s, for which there are genetic markers but no cure, many people do not want to know whether they have the gene that makes them more susceptible. However, in some cases, knowing that a child, parent or sibling has a gene will be an indicator that you may have it as well. Siblings may disagree on whether parents should be tested for susceptibility to diseases of old age, and parents may disagree on whether to have a child tested, or how much information to disclose and at what times.
We leave traces of our DNA everywhere. Most of the dust in your home is dead skin cells from your family and guests, which includes their DNA. We leave DNA on cutlery in restaurants, on coffee mugs at work, and on the floor of the hair salon. Genome sequencing will soon be so cheap and ubiquitous that it may become very easy for someone to get a DNA sample and have a copy of your genome without your knowledge.
We have decisions to make, collectively and individually, about the management of our genetic information. The more research that is done, the more diseases we can cure, and the better it will be for all of us. However, we must balance this with our needs for privacy and the right to control the use of our DNA. Make sure you know your rights, and take the time to understand the implications before sharing your DNA.