Rare Genetic Variations – Not so Rare.

‘Rare’ genetic variants are surprisingly common, life scientists report

Stuart Wolpert – University of California Los Angeles Newsroom

http://newsroom.ucla.edu/portal/ucla/rare-genetic-variants-are-surprisingly-234074.aspx

“A large survey of human genetic variation, published today in the online version of the journal Science, shows that rare genetic variants are not so rare after all and offers insights into human diseases.

“I knew there would be rare variation but had no idea there would be so much of it,” said the senior author of the research, John Novembre, an assistant professor of ecology and evolutionary biology and of bioinformatics at UCLA.

A team of life scientists studied 202 genes in 14,002 people. The human genome contains some 3 billion base pairs; the scientists studied 864,000 of these pairs. While this is only a small part of the genome, the sample size of 14,002 people is one of the largest ever in a sequencing study in humans.“Our results suggest there are many, many places in the genome where one individual, or a few individuals, have something different,” Novembre said. “Overall, it is surprisingly common that there is a rare variant in the population.

“This study doesn’t tell us how to cure a particular disease but suggests that disease in general may be caused by rare variants, and if you’re trying to find the genetic basis of disease, it’s important to focus on those variants. Understanding the genetic basis of disease provides clues to how the diseases work and clues about how to treat them.”

The scientists discovered one genetic variant every 17 bases, which was a dramatically higher rate than they expected, said Novembre, a population geneticist who is a member of UCLA’s interdepartmental program in bioinformatics.

Most of the time, only one person has the genetic variant and the other 14,001 do not.

“We saw lots of that,” he said. “We discovered there are many places in these 202 genes where there is variation and only a few individuals differ from the whole group, or only one differs. We also see evidence that a substantial fraction of these rare genetic variants appear to be deleterious in a long-term evolutionary sense and might impact disease.”

At the end of reading the whole article one wonders what the implications for autism are ?

Image(s): FreeDigitalPhotos.net

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