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A genome is any organism’s complete set of DNA, including all of its genes. An organism’s genome contains all of the information needed to build and maintain the organism. Accompanied by much fanfare and hype as a ‘landmark in science’, the first draft of the human genome appeared on 12 February 2001. In humans, a copy of the genome with all of its 3,234.83 mega-basepairs is contained in each and every one of the body’s cells.

Knowing the complete sequence of the human genome is similar to having a manual on how to construct the human body. However, this manual has more than 3 billion pages and is not easy to read. Great expectations were raised by the scientists involved with the human genome project. However, understanding how the 3.4 billion complex parts work to create human life, health and disease is a challenge. It is currently estimated that there are 19,000–20,000 human protein-coding genes, although this estimate may be reduced over time. Figure 3.4 gives a graphical representation of the idealized human karotype showing the organization of the genome into chromosomes. The drawing shows both the female (XX) and male (XY) versions of the twenty-third chromosome pair.

Figure 3.4 The idealized human karotype divided into 23 chromosome pairs

Source: Public domain

With the human genome project came the formation of new organizations to capitalize on the project. The National Institutes of Health/National Human Genome Research Institute is steering many research programmes on the human genome. One objective is to identify any gene suspected of causing an inherited disease. More than 2,000 genetic tests enable patients and families to be informed about their genetic risks for disease and to help professionals diagnose disease. The cost of sequencing an individual’s genome is being reduced to below US$1,000. When this cost eventually falls, people will be able to carry copies of their karotype on their smart phones. Comparative genomic studies are identifying the causes of rare diseases. These scientific advances do not come without consequences for human liberty, privacy and rights.

Ethical, legal and social implications may affect individuals, families and the whole of society in four areas:

 Privacy and fairness in the use of genetic information, including the potential for genetic discrimination in education, employment, immigration and insurance. There is potential for a new, indelible type of stigmatization.

 The integration of new genetic technologies, such as genetic testing, into the practice of clinical medicine.

 Ethical issues surrounding the design and conduct of genetic research with people, including the process of informed consent. People will need the right to refuse the holding of their genome in databases.

 The education of health care professionals, policy makers, students and the public about genetics and the complex issues that result from genomic research.

We inherit from our parents all of the information necessary to create the proteins that make up our bodies. This inherited information, together with the influence of the environment, creates the complete human being. Much research has focused on the obvious question: How important is heredity and how important is the environment in human behaviour, health and well-being?