Twenty years ago, when the proposed project to sequence the entire human genome was under consideration, both the promise and to some extent the peril were subjects of active discussion. The promise was seen to lie in the potential for deducing the way the human organism is formed and works. From that could come understanding of what goes wrong, leading to birth defects as well as ailments of later life. In turn, that understanding could lead to precise diagnoses, including prenatal diagnosis, prediction of late-onset disorders, and design of preventive measures, specific treatments, and even gene therapy. The promise captured...

The concept that our DNA sequence — our genome — does not equal or predict our destiny has been extremely difficult for some geneticists to accept. We were attracted to this new field of molecular genetics in the 1980s because of the belief that disease-causing mutations would predict patients’ futures. If geneticists could identify the genes responsible for their patients’ diseases and the genetic changes or mutations in those genes, then, we believed, geneticists would be able to predict the clinical courses of their patients’ diseases. Translating into individual terms, physicians would have the information from the laboratory analysis of...

In this chapter we will describe genomics and explore why it developed as a new discipline in science and medicine in the latter part of the twentieth century. Why did genomics capture the imagination of the population and the media so visibly in the early twenty-first century? Consideration of the scientific development and public visibility of genomics is essential to understanding how all of humankind may be influenced by genomics in what is being referred to as the postgenomic era — the period after the sequencing of the initial genomic DNA samples. In this exciting time, the ability to obtain...

Genetic determinism argues that you are your genome — your future is written in your genes. We introduced the topic of genetic determinism in chapter 1, and it will be a thread woven throughout this book, because this concept seems to be a by-product of the Human Genome Project or at least has been given greater visibility because of the project. Taken in its extreme, genetic determinism would deny the possibility of environmental influence on an individual’s development and would suggest that each of us has a genetic blueprint that is set and cannot be modified by our experiences.

This...

Perhaps one of the most lasting conceptual changes to be brought about by the discoveries of the Human Genome Project will be the deconstruction of a human-centered biology. The ability to sequence whole genomes from organisms across evolution has shown that genomes of humans are more similar to those of other organisms than many scientists had appreciated before these sequences became available. Rather than being at the central point in all of biology, humans are learning that biology is a matrix in which they themselves are embedded as integral, but not extra-special, parts. We refer to this as the Copernican...

For many individuals, their identity is dependent on their ancestry and the ethnocultural group to which they belong. But the knowledge within the family may be incomplete or influenced by inaccurate family lore. Clinical geneticists ask their patients for a three-generation pedigree in their initial evaluation. Can you do this for your own family?

Some individuals assume that racial or ethnic group membership of another person allow certain assumptions about that individual, perhaps even their religion or other shared values. As a couple who share an Irish surname, we are well aware of this. Many have erroneously assumed that we...

Just as ethnocultural group membership is important to many individuals’ concept of their identity (chapter 5), we propose that for many, though not all individuals, their gender is at least as important to that self-identity. Our culture generally assumes gender to be dichotomous — male or female. As we will see, however, a simple dichotomy does not adequately address the many possible categorizations of gender and sex, and in fact the same individual may be defined as male in one category and female in another.

The following scenario — the question in the delivery room — is one that occurs...

We have been discussing topics related to an individual’s identity, including ethnocultural group and gender. In this chapter we will discuss the testing for identity using DNA-based forensic analyses.

The courts have long recognized identification of suspects using phenotypic traits including eyewitness testimony of a suspect’s appearance, matching of fingerprints to a database, and laboratory testing of blood type. DNA analysis provides an additional tool and may be used to identify the victim and the suspect and to determine family relationships.

An essential distinction between genetic forensic testing and genetic medical testing is the very different use of the results....

DNA is incredibly personal. Unless you are an identical twin, your DNA is absolutely unique. In fact, even for identical twins there will be a number — a relatively small but very real number — of genetic changes that occur after the splitting of the newly fertilized embryo in the twinning process. So, even identical twins are slightly different at the level of the genomic sequence.

If your DNA is unique, and if you accept that it contributes to your uniqueness as an individual, then most people in the United States would argue that your DNA is yours. This cultural...

In chapter 8, we discussed groups, such as the Navajo, in which genes are not private entities but rather “belong to” or “are controlled by” the group and not individuals. For those who come from a different culture, for example, the dominant U.S. culture in which individuality is such a powerful value, it may be difficult to come to an understanding of group control of something that is so important to one’s own biology. But as shown by the examples we selected, the group’s leaders — be they French or Navajo — have the interests of the group, and therefore...

Genetic discrimination is the use or potential use of an individual’s genetic information in decisions regarding employment and insurance, including life and health insurance. Discriminatory behavior includes actions against the individual’s best interests based on this genetic information and without regard to the individual’s merit. Discrimination occurs when information typically used to consider other individuals has been subordinated to, or supplemented by, an individual’s genetic information. Decisions made by an employer or insurer involving the use of genetic information in a routine or blanket manner pertaining to all individuals concerned also represents a discriminatory practice.

Genetic information used in this...

Humans have entered an era in which many infertile couples are able to have babies. Those at risk for genetic diseases can have normal offspring. And some think that humans are not that far away from a time when scientists will be able to improve upon the human species by expanding options beyond those offered by evolution — evolving faster and better than will occur naturally — using technology to design the best babies who will grow to be better adults (chapter 3).

We will consider a variety of reproductive technologies, since they permit access to reproduction for those who...

Normal sexual reproduction occurs when the sperm containing one set of twenty-three chromosomes fertilizes an egg containing another set of twenty-three chromosomes to form a zygote, or single-cell fertilized egg, containing two sets of the twenty-three, or forty-six chromosomes. Reproductive cloning occurs when the nucleus is removed from an egg and replaced with the nucleus of an adult somatic cell containing forty-six chromosomes, and then the clonal zygote is stimulated to divide and develop into an embryo. The process of cloning in this manner is therefore called somatic cell nuclear transfer (SCNT). The fetus has the same nuclear DNA as...

When we are born, our bodies are built to last a century or more. Do you know of any machine so durable that it would not require replacement parts in the course of one hundred years of operation? This means that our tissues must have mechanisms to deal with the wear and tear that they all experience. This is not simply the damage imposed by external trauma but also the tissue stress and strain of normal life. Our cells are in states of constant metabolism and are carrying out the functions for which they were designed. These functions lead to...

Gene therapy involves the substitution of a normal genetic sequence in place of a disease-causing genetic sequence. A tremendous future promise for gene therapy has been suggested by many physicians and scientists over the last twenty to twenty-five years, and we were convinced by the early speculation. In the 1980s, when patients and their parents asked us how long it would be before gene therapy clinical trials would be available to help them with their metabolic disease, our response was that it would be five years. Then came the realization that we had been giving this five-year time frame for...

The concepts that we discussed in this book are changing not only biology and law enforcement but also the practice of medicine. As we recognize the individuality of each one of us, we need to begin to tailor the medical management to the individual. In this chapter, we will explore how advances in genomic sciences are changing fundamental approaches to, and the very culture of, clinical medicine.

Medicine as practiced today is geared toward acute intervention when a clinical condition presents suddenly and unexpectedly, often with the patient in crisis. Patients with chronic illnesses, who would have succumbed to their...

In this book, we have attempted to refute the concept of genetic determinism — that individuals are the products of their individual genomes. We argue that the expression of your genome is altered by your experiences, and therefore even if the DNA in your genome could be sequenced, your future would not be known. Your destiny would remain hidden.

We have shown that genetic determinism infuses all of the areas touched by genetics and genomics. Yet there is absolutely no biological basis for such deterministic views. Identical genomes exposed to differing environments — and environments always will differ in some...