The Human Genome Revisited

You may not realize it, but for years scientists considered the vast majority of our DNA - about 98% - as "junk" protein, since these sequences don't encode genes and were assumed to do nothing.

But that idea is being challenged by hundreds of researchers from a revolutionary international project called ENCODE, which stands for Encyclopedia of DNA Elements.

Their studies over the past five years suggest that more than 80% of the human genome is used for something important in keeping us healthy.

This group of non-coding DNA elements may enhance, promote, and regulate the massive, precise interworkings of cellular function. They can determine whether our proteins end up working properly, which is crucial in cells.

Studies are now pointing to genetic diseases that originate near or within these non-coding DNA sequences. For example, a rare brain disorder called Ravine encephalopathy causes severe anorexia in infants. It's due to a defect in a non-coding DNA sequence that leaves neurons unstable and degenerates the brain's white matter.

Beyond helping us understand that particular disease, the significance of ENCODE's results is that it takes us a step beyond the human genome project which first laid out the genes. Now, after studying 150 different cell types, ENCODE defines and explains the roles of our genes, revealing the marvelous complexity of the human genome that can signal 20,000 genes at the exact time and location to allow a fetus to develop normally.

The ENCODE project provides a rich source for many more years of excitiing research.