DNA breakthrough holds promise of new treatments: New Zealand scientists

A discovery on how DNA affects the genes that determine our height could lead to a breakthrough in treating growth disorders and other ailments, New Zealand scientists said Tuesday.

The New Zealand research found that our height is not simply governed by the genes written in our DNA, but also how the DNA is folded inside our cells.

University of Auckland researchers claimed they had, for the first time, pinpointed how sections of DNA, known as SNPs (single nucleotide polymorphisms), influenced genes that determine height.

SNPs were points in the DNA that commonly varied between individuals and had been linked to a disease, study leader Dr Justin O'Sullivan said in a statement.

Researchers screened 700 SNPs, and found evidence that 10 percent -- 68 -- made contact with genes known to be involved in height.

"Height carries status in Western societies," Professor Wayne Cutfield said in the statement.

"Extremely short children are very socially disadvantaged. Currently, they're treated with growth hormones, but this doesn't work for everyone."

The SNPs finding lent weight to a new way of thinking about DNA and the human genome that was gaining traction among geneticists.

"There was this idea that mapping the human genome would reveal everything about human development and disease," said O'Sullivan.

"The full human genetic sequence was published 13 years ago, but many mysteries remain. It's now becoming clear that we also need to understand the other forms of information in DNA that affect how genes are read and used."

Unwound, the DNA that made up the human genome was about 2 metres long. To fit into a cell nucleus, the DNA was tightly coiled around disc-like proteins, like thread around bobbins.

Through this coiling, segments that were far apart when the DNA was stretched out, come into contact with each other.

"The theory is that SNPs outside the genes are changing the activity of the genes they make contact with, causing them to overproduce or under-produce certain proteins, and this is what causes the disease -- or, in the case of height, extreme short stature," said O'Sullivan.

Experiments clearly demonstrated that some of the SNP gene interactions changed the way genes were read.

"The SNPs are messing with the cell's genetic recipe," said O'Sullivan.

The researchers were now applying the technique to try to gain some new understanding of rheumatoid arthritis, obesity, diabetes and gout.

It was possible that medicines could be developed that neutralized the distorting effects of SNPs, restoring biochemical balance, said O'Sullivan.

"This really opens new doors for us. We believe this approach ultimately will lead to new gene-based treatments for many conditions." Endit