The principal aim of this truly international research venture, co-ordinated by the Human Genome Organisation (HUGO), is the creation of what has been called a ‘handbook of life’ — the mapping and sequencing of human DNA to characterise the human genome, and the provision of detailed information about the structure, organisation and function of human DNA from many sources.

The driving force for the project is to create a bank of genetic information that will help to increase both human understanding of the biological processes that go on inside the body and the potential for the diagnosis and treatment of diseases that affect human individuals and groups.

In the autumn of 2000, the Human Genome Project will publish the first rough map of the 24 chromosomes that make up the human genome. It is still some considerable way from producing the ‘high definition’ map that is its ultimate goal.

Other aims of the HGP include:

• Mapping and sequencing the DNA of other ‘model’ organisms widely used in biological research, eg the fruit fly.
• Developing methods and equipment for genomic analysis.
• Examining the ethical, legal and social implications of human genetics research.
• Training scientists and technicians to use new analytical methods and equipment.
• Initiating and pursuing biomedical studies that have the aim of improving human health.
• Generating public awareness and discussion of issues arising from human genome research.

The publicly funded Human Genome Project is, to a degree, in competition with private corporations that have a commercial interest in patenting some of the genetic information they uncover.

The Human Genome Diversity (HGD) Project

This project to analyse and record the genetic variation among humans, is much more than just a simple analysis of genetic materials. It involves not only geneticists but also medical practitioners, anthropologists, language experts and researchers from many other disciplines. The aims include:

• Gaining insight into human biological history.
• Throwing light on biological relationships within and between different human groups.
• Gaining an increased understanding of the causes of particular human diseases and how they might be more effectively treated.

One kind of genetic variation being studied, relates to diseases that affect only certain populations or individuals. Often the variation in susceptibility to disease is due to environmental factors such as diet and exposure to parasites. But genetic pre-dispositions are also likely to play their part. DNA data, in association with statistical data about how different populations are actually affected by different diseases, may help researchers to identify genetic factors which may be associated with those diseases. Such information could be used to find ways of treating or preventing those diseases, or — as the programme reveals — be misused to target certain groups of people by using biologically active materials that threaten life instead of trying to save it.

Variations in the Human Genome

All humans, no matter what their ethnic origin, have around 100,000 genes encoded within the 46 chromosomes that make up the human genome. It is these genes that determine the traits that children inherit from their parents.

Most of the genes are identical in all humans, although they may contain minute differences that in most cases, have no effect on function. However, in some cases, even a single alteration in the sequence of base pairs that makes up the DNA can lead to susceptibility to disease, or perhaps resistance to disease. Other variations result in differences in physical features such as eye colour, blood group, height or hair colour.

The more closely two people are related, the more likely they are to have the same variant genes — known as alleles. Groups of people with common ancestry — ethnic groups — are more likely to share particular alleles, and hence physical traits or biological susceptibilities, than people from a different ethnic origin.

But although there are often distinct genetic differences between groups, the differences are very small compared with the genetic similarities. And individuals within an ethnic group are, in genetic terms, more different from each other than their group, on average, is from other ethnic groups. Also, ethnic groups are defined at least as much by their culture as by their genes.

Genetic Engineering (sometimes called Gene Manipulation)

Genetic engineering is a planned alteration to the genetic make-up of a living organism. The process relies on the use of what are called vectors (based on viruses) or of bacterial components known as plasmids) to introduce new DNA into living cells.

Genetic engineering may be used for a variety of purposes, including:

• Investigating the metabolic pathways occurring in living organisms.
• Enhancing or altering the characteristics of living things.
• Enabling cells to produce protein products that they do not naturally make, for example, vaccines and other medically valuable compounds.
• Repairing a genetic defect, a process often called ‘gene therapy’.