Genes - the chemical messages of heredity - constitute
a blueprint of our possibilities and limitations. The legacy of
generations of ancestors, our genes carry the key to our similarities and
our uniqueness.
When genes are working properly, our bodies develop and function
smoothly. But should a single gene - even a tiny segment of a single gene
- go awry, the effect can be dramatic: deformities and disease, even
death.
In the past 20 years, amazing new techniques have allowed scientists to
learn a great deal about how genes work and how genes are linked to
disease. Increasingly, researchers are able to identify mutations, changes
within genes that can lead to specific disorders. Tests for gene mutations
make it possible not only to detect diseases already in progress but also,
in certain situations, to foresee diseases yet to come.
This new ability raises both high hopes and grave concerns. On the one
hand, predictive gene testing holds out the possibility of saving
thousands of lives through prevention or early detection. On the other,
the implications of test results are enormous, not only for the individual
but also for relatives who share this genetic legacy, and for society as a
whole.
This booklet presents key concepts and issues relevant to gene testing
and answers questions that are frequently asked about the techniques,
potential risks, and possible benefits of attempts to link genetic markers
with disease. Words that appear underlined in the pages that follow are
defined in the Glossary. Clicking on these words will take you to the
glossary. From there press the browser's back button to return.
