approximately 2,000 genes identified, and over 4,000 diseases caused
by genetic defects, genetic testing is becoming an increasingly important
part of preventive medicine.
Genes are groups of proteins
that are present in every cell in your body. Genes are found in chromosomes
and they control growth and help you stay healthy. Sometimes, when genes
are abnormal or damaged, they may not work properly, which may lead
to disease. Some genetic abnormalities, or "gene mutations,"
may run in families. Some just happen by chance. Sometimes one mutation
can cause a person to have a disease, but most diseases are caused by
a combination of genetic and environmental factors.