Understanding Biotechnology

What is Biotechnology

Overview of Biotechnology

History of Biotechnology

Why do we do biotechnology?

Biotechnology for the environment

Biotechnology for food and agriculture

The revolution began with a fundamental discovery which opened the door to a new level of scientific understanding in the field of genetics. The discovery of the chemical basis of life - the DNA molecule - happened in the early 1950s. More than 50 years later, the mapping of the human genome has provided a framework to identify each human gene and the specific roles they perform.

Scientists are also mapping the genetic codes of bacteria, viruses and other disease-causing organisms, and discovering how their genes interact with our own to cause disease. Scientists can also read the DNA of individual humans to compare their genetic characteristics with our rapidly advancing knowledge of the roles of each human gene. In the future, it may be possible to develop individual “genetic profiles”, to allow comparison with a much wider range of genetic conditions and predispositions than is currently known – and these could be contained on just a single microchip.

Other fact sheets in this series outline how biotechnology is working to enhance the practise of medicine in specific areas (see below). Here we provide an overview and some examples of this new era of biotechnology in medicine

Diagnosis

Preventative health care

Heightened susceptibility to breast cancer has already been linked to several genes. This knowledge could help women who carry those genes to exercise increased vigilance by having scans more frequently than would be recommended for the general population. In coming years the specific roles of these and other genes will be better understood, as will the roles of genes in other diseases, and the interactions between genes and the environment.

People with a genetic susceptibility to diabetes, osteoporosis, heart disease or other disorders could be guided to shape their diet and lifestyle to prevent their onset, and to reduce the risk of contracting many kinds of cancers which are caused by a combination of genetic and lifestyle factors.

Many people value the advantage of using their personal genetic knowledge to enhance their health, but this kind of knowledge is not necessarily welcomed by all. The issues it can raise can be difficult for individuals to deal with when they discover they you have a predisposition to an illness, while people without such a predisposition may become dangerously complacent about their health. Patients can choose not to know their genetic status for particular diseases and conditions, or can withhold information from others (see Genetic Privacy). Counselling is required at all stages of the decision-making process.

Whole-of-life medicine

In some cases, parents of a child with an inherited disorder can pursue the option of curing the illness by having another child with the same tissue type, but lacking the gene causing the disorder. Ensuring that the second child has the same tissue type as its brother or sister involves using pre-implantation genetic diagnosis. Embryos created through in vitro fertilisation are screened, and those with the same tissue type as the ill sibling are implanted in the mother. When the baby is born, stem cells can be taken from its umbilical cord blood and transplanted to the sick child in the hope of treating the condition. In early 2004 a Melbourne family were the first Australians to benefit from this kind of treatment which applies techniques developed for in vitro fertilisation (IVF).

Stem cells from the umbilical cord of the couple’s second child were infused into the bone marrow of their first child who had inherited an immune deficiency disorder. These cells were not rejected because the tissue compatibility of the children had been confirmed by analysis of the second child’s DNA before the embryo was implanted in the mother’s womb. The analysis also confirmed that the second child had not inherited the genes which caused the firstborn’s illness. The infused stem cells survived and multiplied, correcting the firstborn’s immune deficiency which would otherwise have caused lifelong suffering and possible premature death.

All these treatments raise complex ethical questions (see What are bioethics?) and access to IVF for the purpose of creating a second child to treat the first must be approved by the relevant ethics committees.

Pharmaceuticals

By studying the genetics of viruses, fungi and bacteria that infect humans, we can understand how they cause disease and develop drugs that target them more specifically. Many approaches to treating HIV/AIDS and other viruses target their genetic makeup. Others, such as the Relenza treatment for influenza developed by Australian company Biota, rely on knowledge of the molecular structure of proteins on the surface of the influenza virus to stop an infection spreading.

Organ and tissue replacement