In 2003, the New York Times headlined: "Scientists Say Human Genome is Complete", journals Science and Nature also printed similar headlines, unveiling the historic achievement.

But that wasn't true.

"As a matter of truth in advertising, the 'finished' sequence isn't finished," said Eric Lander, who led the lab at the Whitehead Institute that deciphered more of the genome for the government-funded Human Genome Project than any other. "I always say 'finished' is a term of art."

"The human genome has not been completely sequenced and neither has any other mammalian genome as far as I'm aware," said Harvard Medical School bioengineer George Church, who made early advances in sequencing technology.

So why did they say it was finished?

Limited technology 14 years ago

Technically, when scientists finished the first draft of the human genome in 2001 – and again the final version in 2003 – no one lied, exactly, because they sequenced it to "as complete as it can be", given the available technology at that time.

Nobody paid much attention to the details as the missing sequences did not seem to matter. But new findings suggest that they may play a role in conditions such as cancer and autism now.

"A lot of people in the 1980s and 1990s [when the Human Genome Project was getting started] thought of these regions as nonfunctional," said Karen Miga, a molecular biologist at the University of California, Santa Cruz. "But that's no longer the case."

Some of them, called satellite regions, misbehave in some forms of cancer, she said, "so something is going on in these regions that's important."

Now, with new sequencing technology on the rise, scientists are keen on revisiting "tough-to-sequence regions (that) frequently have important genes," said Michael Hunkapiller, chairman and CEO of Pacific Biosciences, which makes DNA sequencers.

These regions have been theorized to contain actual protein-making genes and there is also evidence that these non-gene parts, especially DNA stutters "clearly have disease implications," Hunkapiller said.

"Three-quarters of the [genome] differences between one person and another are in [such] variants" rather than single-letter spelling differences in A's, T's, C's and G's which get all the attention.

In a 2007 paper, Craig Venter and his team showed that there are more person-to-person differences like this, called structural variants, than there are single-letter changes. Yet 90% of these are not sequenced, either by the HGP or a later effort called the 1000 Genomes Project.

The Human Project: Looking at genetic diseases holistically

But uncovering the secrets of genetic diseases might even get easier with "The Human Project" that the New York University is currently rolling out. It is looking at recruiting 10,000 New Yorkers interested in advancing science by sharing personal information such as cellphone locations, credit-card swipes, blood samples and life-changing events – for 20 years.

The project would collate data that could provide insights into of health, ageing, education and many other aspects of human life.

"That's what we're all about: putting the holistic picture together," says project director Dr Paul Glimcher, a New York University neural science, economics and psychology professor.

There are many other "big data" health studies, including one by the National Institutes of Health (NIH) that looks at a million people to foster individualised treatment.

Tests of everything, from blood to genetics to IQ, will be looked at. Follow-up blood and urine tests ̶ and an at-home faecal sample ̶ will be requested every three years. Behavioural aspects of life and lifestyles will also be recorded as the researchers hope that the results will illuminate the interplay between health, behaviour and circumstances, potentially shedding new light on conditions ranging from asthma to Alzheimer's disease. MIMS

Read more:

Are we over-propagandising genetic research?
Project to synthesise human DNA creates tension after public announcement
Human knockouts: A way to decipher why some drugs work, while others fail