Updated map of human genome to help fight against disease

(AFP)

Scientists on Wednesday published the best-ever map of key variations across the human genome, an exploit aimed at honing the fight against inherited disease and gaining insights into our species' odyssey.

The map focuses on so-called copy number variations, or CNVs -- segments in the genetic code that may be deleted or copied.

Such changes, it is thought, can provide clues about a range of diseases and about human evolution.

The research, released by the British science journal Nature, entailed scanning and comparing the genome of 450 people of European, African or East Asian descent.

The results show that any two genomes differ by more than 1,000 CNVs, or around 0.8 percent of a person's DNA code. Most of these CNVs are deletions and only a small number are duplications.

"The study is more than 10 times as powerful as our first map, published three years ago and much more detailed than any other," said one of the project's leaders, Matt Hurles with Britain's Wellcome Trust Sanger Institute.

The team caution, though, that so far the map has yet to yield secrets about susceptibility to complex, multi-gene diseases such as heart disease or diabetes.

Even so, some intriguing nuggets have been unearthed about genomic basics.

One is that we have 75 "jumping genes" -- regions of the genetic code that can be found in more than one location in some individuals.

Another is that more than 250 genes can lose one of the two copies that we have in our chromosomes and yet not inflict any obvious ill consequences for health.

In addition, 56 other genes can meld together, potentially forming new composite genes.

"The genetic 'blueprint' of humans is the human genome," Mark Walport, director of the Wellcome Trust, said in a press release.

"But we are each unique as individuals, shaped by variation in both genome and environment. Understanding the variation amongst human genomes is key to understanding the inherited differences between each of us in health and disease."

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