In 2003, scientists participating in the Human Genome Project, which began in 1990, completed a sequence of the nearly 3 billion "letters" that spell out human genetic instructions. This dramatic advance will change medicine forever, as scientists speed toward their goal of identifying all of our genes and learning what they do.
This advance follows two decades of rapid progress in human genetics, the branch of biology that studies heredity. Scientists have discovered many genes that play important roles in human diseases.
For example, the gene defect responsible for the most common inherited form of mental retardation—fragile X syndrome—was identified by March of Dimes grantees. Other findings identified specific gene mutations (changes) responsible for:
- Cystic fibrosis, an often fatal disorder of the lungs and digestive system.
- Achondroplasia, a form of dwarfism.
- The neurofibromatoses, inherited diseases of the nervous system.
- Retinitis pigmentosa, a group of inherited conditions causing vision loss.
- Some hereditary forms of heart disease.
- Familial breast and colon cancer.
The pace of such discoveries should come even faster, now that scientists have a nearly complete catalog of our genes. Identifying disease-causing genes can be a first step toward developing specific treatments, such as new drugs or gene therapy, in which a healthy gene is used to replace one that is missing or faulty.
Knowing more about our genetic makeup also should lead to a more individualized approach to preventive medicine. You may be able to be tested to learn whether you are specially susceptible to certain diseases, so that you can take steps to prevent them.
