For decades, researchers suspected that genes played a role in the development of cardiovascular conditions such as heart disease. Heart-related conditions tend to run in families, which suggests a genetic component is being passed from generation to generation. In combination with one’s environment (e.g., eating a high-fat diet, genetics appeared to play an important role in the development of high blood pressure (hypertension), high cholesterol and other conditions. However, the necessary technology to test this idea was not available.

A major advance in gene therapy occurred in the 1980s, when researchers learned how to transport healthy genes into human cells. They did this by grafting the healthy genes onto a weakened virus (an adenovirus), which was then injected into cells. The weakened virus then “infected” the cells with the healthy genes, causing the cells to follow the healthy new blueprint instead of the old harmful blueprint. The weakened virus was then easily destroyed by the body’s immune system.

In the 1990s, this strategy of gene therapy successfully treated a young woman’s case of hypercholesterolemia (extremely high cholesterol due to a genetic defect). Other human gene experiments followed. 

The advances of gene therapy and its potential have been greatly helped by the Human Genome Project. This scientific collaboration of government research bodies and some private companies created a blueprint to map all the genes contained in the human genome. The Human Genome Project started as a result of conferences held in the late 1980s and coordinated work in the United States began in 1990. The project was completed in 2003. In 2001 and 2003, drafts of the sequencing of the human genome were published by the government consortium and also by Celera Genomics, a private biotechnology company also working on the human genome.

In April 2003, the (U.S.) National Institute of Environmental Health Sciences announced that it had catalogued 200 genes identified with such diseases as cancer, vascular disease, heart disease and asthma.