Overview
Genetics and genetic counseling are not terms that were familiar to people in decades past. However, the discipline of genetics is approximately two centuries old, and will continue to progress and influence life as we know it.
The Past
The genetics discipline began with Gregor Mendel, an Augustinian Monk from Austria who was far ahead of his time. He pioneered genetic research by carrying out selective breeding experiments on pea plants. He is responsible for some very important laws in genetics. It wasn't until 1903 that the theory that genes are located on chromosomes in the cells of the human body was introduced. Two years later, the first scientific report was published on the inheritance pattern of a genetic, autosomal dominant disease. In the late 1940s and 1950s, some doctors were starting to recognize the importance of heredity in medicine and a few "hereditary counseling clinics" began to emerge across the United States. That fact that genetic information carries a psychological aspect with it was recognized in 1947 when Dr. Sheldon Reed introduced the term "genetic counseling." Even though there were no genetic tests at this time, and no genes were identified, physicians could try to elucidate the inheritance pattern within a family and calculate the recurrence risk for other family members. Physicians could counsel families about what information was known and how to cope.
The Present
In 1990, the National Institutes of Health and the Department of Energy initiated the Human Genome Project to determine the genetic sequence of the human genome. This endeavor is in its final stages and will likely influence the way that medicine is practiced in the future.
Genetic predisposition to numerous, common adult-onset illness is still something that sounds elusive to some physicians. As Collins and McKusick point out, until recent times, many health care providers considered medical genetics the area of expertise of genetic specialists. Victor McKusick, often called the "father of medical genetics," and Francis Collins, the director of the National Human Genome Research Institute, along with many other genetic professionals feel that medical genetics will soon be a discipline not only practiced in tertiary care centers, but also will play a large role in a primary care setting. These scientists note that with the exception of some cases of trauma, almost all human illness, ranging from mental illness to cancer, has a hereditary component. Some common diseases that are just beginning to be considered in the primary care setting, and certainly have sufficient evidence to be considered include:
- Hereditary cancer syndromes
- Adult onset diabetes (diabetes mellitus)
- Heart disease
- Elevated cholesterol
- Asthma
- High blood pressure
- Select psychological illness
While the aforementioned illnesses do not follow simple patterns of genetic inheritance, they all have important hereditary components, some of which will soon be unraveled. As the genetic basis of these diseases are revealed, much will become clear about their pathogenesis, including potential environmental risk factors, better diagnostic tools, preventative care, and improved therapies.
Regarding genetic counseling, in the 1990s, this profession established itself as a recognized specialty. The importance of the educational information counselors provide, along with the short-term psychotherapeutic process clients receive became evident to many. With any genetic risk that is given to an individual, or with any genetic diagnosis, genetic counselors are available to help clients understand what the new information presented to them means and help them adjust to it. The psychotherapeutic process necessitates that the genetic counselor be empathetic, skilled in therapeutic techniques, and value neutral, so as not to inflict his/her beliefs onto a client.
Genetic counselors are being found in increasingly diverse work settings. Currently, and for the past several years, it was common for a master's trained genetic counselor to work with a medical geneticist in a pediatric setting, in a prenatal/preconception setting, in specialty clinics, in cancer genetics, or in adult genetic clinics. Now, genetic counselors can be found working in laboratories, as research or clinical study coordinators, as web developers (often specializing in scientific, medical, or social-work related web sites), in the pharmaceutical industry, and in many other settings. The scientific and therapeutic skills that most genetic counselors possess enable them to add a significant level of skill and perspective to many different career opportunities. As science and technology progresses, it is likely that the roles genetic counselors play in society will further diversify and progress.
The Future
We are embarking on perhaps one of the greatest accomplishments in scientific history. In April of 2003 the completed human genomic sequence will be released; all 3 billion base pairs of the human genome will be known. The enormous effort to decipher the genetic code was made possible because of the international efforts dedicated to the Human Genome Project. This accomplishment is likely just the tip of the iceberg. Even though the genetic sequence will be known in its entirety, there is still a plethora of information that we do not know. There are numerous genes that we have yet to find. There are still many multifactorial conditions that have several genetic components that interact with the environment, such as heart disease, that must be figured out.
Collins and McKusick predict that within ten years predictive genetic tests will be available for several common conditions, such as late onset diabetes, cancer, cardiovascular disease, and dementia. Thus, for individuals who wish to know their level of susceptibility, they could seek genetic counseling and genetic testing. It is inevitable that other single-genes that cause disease will be found. However, this will place us in the same situation that we are currently in for some genetic conditions: we can diagnose them, but there is no effective treatment or cures available to individuals with such conditions. It is and will remain to be a very personal decision whether to have genetic susceptibility testing. Individuals will need to be thoroughly informed of all pros, cons, risks and benefits so that an informed decision can be made.
Three to five percent of the Human Genome Project's budget was allocated to research on the ethical, legal and social implications of the consequences of obtaining genetic information about the human genome. Many experts have predicted that with the increased knowledge about the genome will come issues such as privacy issues, genetic discrimination on the level of employment, health and life insurance and social discrimination. Also, increased genetic information will create social dilemmas. For example, if the technology exists to genetically test for late onset disorders that are not treatable, people will be placed in a difficult situation. They can make the decision to live life and not dwell on their genetic blueprint, or they can take the information and use it to tailor their lifestyle.
One of the most exciting discoveries that is predicted to result from the completion of the Human Genome Project is information on common disease. Most of the common diseases that plague society have a genetic component that is intermingled with environmental factors, such as level of exercise, diet, the time one spends in the sun, etc. Diseases such as heart disease, colorectal cancer, developmental delay, dementia and psychological conditions, breast and skin cancer will become better understood. It is predicted that five to ten, or even more genes all interplay with environmental factors and confer a risk for a given multifactorial disease.
Because many of the common diseases that do have a genetic component are seen in the office of primary care doctors, it is likely that health care will change in the future. Primary care providers will need to become more educated on the genetic factors that are uncovered and the ways to treat based on these genetic factors. They will have to learn the skill of genetic counseling or employ more genetic counselors in order to meet the need that is likely to exist in the future.
The future of genetics is, without a doubt, going to be an exciting future. Genetic counseling will inevitable play an increasingly important role. Genetic counselors will continue to explore the meaning of genetic test results with clients and their families and help them to adjust to this information.