Genetic variation in humans mapped

Scientists have developed a comprehensive map that can help point the genetic causes of differences between people, providing powerful clues for diagnosis, prognosis and intervention of different diseases.
The study led by researchers from the University of Geneva (UNIGE)'s Faculty of Medicine, offers the largest-ever dataset linking human genomes to gene activity at the level of RNA.
Understanding how each person's unique genome makes them more or less susceptible to disease is one of the biggest challenges in science today, researchers said.
Geneticists study how different genetic profiles affect how certain genes are turned on or off in different people, which could be the cause of a number of genetic disorders.

The study conducted by over 50 scientists from nine European institutes, measured gene activity (gene expression) by sequencing RNA in human cells from 462 individuals.
The study adds a functional interpretation to the most important catalogue of human genomes.

"The richness of genetic variation that affects the regulation of most of our genes surprised us," said study coordinator Tuuli Lappalainen.
"It is important that we figure out the general laws of how the human genome works, rather than just delving into individual genes," said Lappalainen.
The biological discovery was enabled by a staggering amount of RNA data from multiple human populations.

"We have set new standards for production, analysis and dissemination of large RNA-sequencing datasets," said Peter 't Hoen from Leiden University Medical Center, who coordinated technical analysis of the data.
Knowing which genetic variants are responsible for differences in gene activity among individuals can give powerful clues for diagnosis, prognosis and intervention of different diseases, researchers said.
Emmanouil Dermitzakis, who led the study, emphasised that the study has profound implications for genomic medicine.
"Understanding the cellular effects of disease-predisposing variants helps us understand causal mechanisms of disease," Dermitzakis said.
"This is essential for developing treatments in the future," he said.

The study was published in journal Nature.