Gene mapping project offers new clues about humans

* 95 percent of human genetic differences cataloged

* Findings offer new tools for studying disease

* More discoveries yet to come, team says

By Julie Steenhuysen

CHICAGO, Oct 27 (BestGrowthStock) – Early data from the 1,000
Genomes Project, an international effort to build a detailed
map of human genetic variation, is already offering new clues
about human disease, including why some people are more
severely affected by disease than others.

Dr. Evan Eichler of the University of Washington in Seattle
and colleagues used findings from the pilot phase of the
project to identify subtle differences among people in areas of
the genome where DNA sequences are often repeated many times.

“I believe this is where we will make huge inroads in
understanding the genetic basis of human disease,” Eichler
said.

His findings were released online on Wednesday in the
journal Science to coincide with publication in Nature of the
first data from the 1000 Genomes Project — a public-private
effort that aims to map to sequence and compare the genomes of
2,500 people from several different regions of the globe.

The data is expected to offer researchers a new set of
tools to help understand the genetic causes of disease.

Eichler said differences in DNA sequences, known as copy
number variation, have traditionally been difficult to compare,
but they may explain why some people have certain diseases but
not others.

And they may also explain why some people are more severely
affected by disease than others.

Duplications of segments of the genome appear to have led
to many of the qualities that distinguish human beings from
other primate species, Eichler told a press briefing.

And they also may be linked with diseases like
schizophrenia and autism, he said.

RAPID GAINS

The findings are possible because of advances in machines
that sequence genetic information made by companies such as
Illumina (ILMN.O: ) and Roche (ROG.VX: ).

These are allowing researchers to make rapid gains in their
understanding of all of the different variations in human
genes, researchers from the 1000 Genomes Project team said on
Wednesday.

“Already, just in the pilot phase, we’ve identified over 15
million genetic differences by looking at 179 people. Over half
of those differences haven’t been seen before,” said Dr.
Richard Durbin, group leader of the Wellcome Trust Sanger
Institute and co-chair of the 1000 Genomes Project.

“This is the largest catalogue of its kind, and having it
in the public domain will help maximize the efficiency of human
genetics research,” Durbin told a news briefing.

The pilot includes data from more than 800 people,
highlighting around 16 million variations in the genetic code
that were previously unknown.

Durbin said researchers now know 95 percent of the genetic
variants in any individual, which will help as teams try to
assess the genetic causes of both rare and common genetic
diseases.

The team found that each individual carries a significant
number of potentially dangerous genetic mutations, with maybe
250 to 300 genes that have defective copies.

And they said the new map will allow researchers to look at
the effects of recent evolution on the human genome.
(Edited by David Storey)

Gene mapping project offers new clues about humans