Never-before-seen human genome variations uncovered

Using a new genome sequencing technology, researchers have uncovered thousands of never-before-seen genetic variants in the human genome.

The findings could be a game changer in better identifying people with risk of certain diseases.

The technique, called single-molecule, real-time DNA sequencing (SMRT), may now make it possible for researchers to identify potential genetic mutations behind many conditions whose genetic causes have long eluded scientists, said Evan Eichler, lead researcher and professor of Genome Sciences at the University of Washington in the US.

"We now have access to a whole new realm of genetic variation that was opaque to us before," Eichler added.

Using the new approach, the researchers were able to identify and sequence 26,079 segments that were different from a standard human reference genome used in genome research.

Most of these variants, about 22,000, have never been reported before, Eichler said.

These discoveries close many human genome mapping gaps that have long resisted sequencing, the study noted.

The SMRT technology used in the new study makes it possible to sequence and read DNA segments longer than 5,000 bases, far longer than standard gene sequencing technology.

This "long-read" technique allowed the researchers to create a much higher resolution structural variation map of the genome than has previously been achieved.

"Knowing all the variation is going to be a game changer," Eichler concluded.

The findings appeared in the journal Nature.