J Craig Venter, who mapped the first draft of the human genome and helped scientists understand how genes shape our lives, has died at age 79.

Venter's death on Wednesday was announced by the J Craig Venter Institute, a genomics research group.

The institute said he died in San Diego after being hospitalised for side effects from a recent cancer treatment.

In the 1990s Venter bet he could use a different sequencing technique to speed up the process of decoding the human genome and beat an enormous government effort called the Human Genome Project.

And in 2000, Venter's private company Celera Genomics announced, along with Human Genome Project leaders, that they had decoded the 3.1 billion sub-units of DNA, the chemical "letters" that make up the recipe of human life.

Three years later, in April 2003, the project declared the genome complete.

"Some have said to me that sequencing the human genome will diminish humanity by taking the mystery out of life," Venter said at a White House event in 2000 about the breakthrough.

"Nothing could be further from the truth."

And his work did reveal even greater mysteries - even as it helped scientists understand the genetic causes for rare diseases and more common conditions such as heart disease and cancer, as well as what mutations or shifts may put people at higher risk of disease.

Venter, who served in the US Navy during Vietnam, said the experience taught him how fragile life could be and made him curious about how the trillions of cells in the human body conspire to create and maintain life.

He also worked at the National Institutes of Health, where he helped develop a technique to quickly identify large swathes of human genes.

Later, he was the first to publish his own sequenced genome with the hope that researchers could scan it to learn what was inherited from each parent and where vulnerabilities to disease might lie, opening doors to one day tailor future treatments to a person's genes.

He and his team also made a breakthrough in synthetic biology by creating a bacterial cell with lab-synthesised DNA.