Whole Genome Sequencing
How Much Information Is Too Much?
by Christina M. H. Powell
As pastors know through their leadership experiences, good decision making requires the right amount of information. Too little information can impair a leader’s ability to make a wise decision and hinder the problem-solving process. Too much information can obscure the information relevant to the decision, create concerns unrelated to the problem at hand, and waste a leader’s time.
In recent years, physicians have looked to a person’s genetic blueprint, called a genome, for insights into the diagnosis and treatment of certain diseases. A person’s genome functions as a biological instruction manual, or genetic book. First, technology allowed doctors to read a few sentences in the genetic book, then a few pages. Now, scientific advances in both biology and information technology make it possible to read the entire book in a couple of weeks. The book not only provides insight into a patient’s current disease, but also reveals the likelihood of medical problems that may occur decades later.
When researchers initially sequenced the human genome in 2003, the effort cost $2.7 billion.1 Now the cost of whole genome sequencing is a mere several thousand dollars and growing less expensive each year. Once an option only for wealthy individuals, soon reading a person’s genetic blueprint will enter mainstream medicine. The question everyone will face is how much information is too much?
Reading the Genetic Blueprint
A person’s genetic instruction manual is written with approximately 3 billion letters. These letters are the rungs on the DNA ladder, pairs of the chemical building blocks adenosine (A), thymine (T), cytosine (C), and guanine (G). These letters combine to make words that direct which amino acids need to join together to make certain proteins. These words combine into sentences, known as genes, which direct the synthesis of tens of thousands of proteins in the human body.
Small genetic variations, like a misspelling in a single word of a book, can lead to diseases or create different responses to medications. Finding the misspelling can help a physician accurately diagnose an illness or choose the correct medication for a particular person. This information can save money and prevent more complicated medical problems.
Sometimes the information tells doctors which word is misspelled, but that knowledge cannot be tied to an effective treatment yet. For example, a young girl with developmental delays of unknown origins learned that her genetic blueprint had a unique misspelling, or mutation, that no other person in the world has been reported to have. In other words, the mutation started in her genetic code and her parents did not pass it on to her. While the information did not lead to new treatment options, the knowledge brought relief that the girl’s younger brother probably would not experience the disease.
Approximately 50,000 babies are born in the United States each year with difficult-to-diagnose disorders.2 These children often wait 3 to 5 years for doctors to determine the cause of their symptoms. Whole genome sequencing, or a similar technique such as exome sequencing, can solve these mysteries in a few weeks. The ability to read the entire genetic book to find the problem is more thorough than guessing which pages might contain important information and skipping through the book to read only those pages. For difficult-to-diagnosis disorders, the ability to read the entire genetic book within a short time period prevents doctors from pursuing treatment avenues that lead to dead ends.
Handling Incidental Information
Ethical concerns surrounding whole genomic sequencing involve the extra information produced by the technique that is not immediately relevant to the diagnosis and treatment of the disease that prompted the sequencing. Some of this incidental information may be useful for predicting future medical needs. Many common medical tests often yield incidental information. For example, an X-ray taken to diagnose a broken bone may show the presence of a developing tumor. The concern with genomic analysis is that incidental findings will crop up for every patient tested.
Some of the incidental findings may help doctors prevent diseases likely to occur within the next few years. Other findings may yield ethical dilemmas. Should a doctor tell parents that their baby is likely to develop cancer starting in middle age? If there is no known cure or prevention for the disease, does this information help or harm the patient and family?
In other cases, knowledge of a future risk may enable preventative changes. A person predisposed to develop diabetes later in life might want to change his or her diet and pursue more physical exercise. In some cases, unknown environmental factors may influence whether or not a person ever develops a disease. Would those patients benefit from such a murky prediction, or would the knowledge only create unnecessary anxiety? How much should parents tell children about information they have learned about that child’s genome?
Forming a Pastoral Perspective
The key to interpreting results from genomic analysis involves understanding the difference between probabilities and certainties. In most cases, our genetic blueprint points to likely, but not definite, medical outcomes. In many cases, our environment matters, and often we shape our environment through our own choices. Even with the ability to read our complete genetic book, we cannot fully predict our biological future.
The Bible teaches in Philippians 4:6, “Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your request to God.” Even when a Christian receives disturbing news, prayer can calm an anxious heart. Jesus instructs His followers, “ ‘Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own’ ” (Matthew 6:34). Christians can plan for the future, but they should not worry about the future.
In practice, the best way to prevent worry may be to choose not to receive certain information. Doctors may be able to give patients the opportunity to see what information they want to know through a web-based solution that allows patients to learn more about their genetic information over time. A parent could choose not to learn about a child’s future cancer risks, but the information would be available if the child wanted to access it after reaching adulthood.
Creative approaches to accessing the data from whole genome sequencing may be the key to solving the problem of too much information. From a spiritual standpoint, a pastor can help parishioners remember God has a plan for a person’s life beyond the plan written in the genetic code. “ ‘For I know the plans I have for you,’ ” declares the Lord, “ ‘plans to prosper you and not to harm you, plans to give you hope and a future’ ” (Jeremiah 29:11).
1. “The Human Genome Project Completion: Frequently Asked Questions.” National Human Genome Research Institute. Found at http://www.genome.gov/11006943. Updated October 30, 2010. Accessed December 5, 2012.
2. Bonnie Rochman, “Why Cheaper Genetic Testing Could Cost Us a Fortune.” Time Health and Family. Found at: http://healthland.time.com/2012/10/26/why-cheaper-genetic-testing-could-cost-us-a-fortune/. Updated October 26, 2012. Accessed December 5, 2012.