Sunday, October 3, 2010
Johns Hopkins scientists specializing in genetic information have discovered 13 genes linked to human body mass. The genes were identified by screening the epigenome and could provide information that can be used to prevent and treat obesity. The authors of the study explained how they discovered the genes and the implications of their discovery to Science Daily:
"Some of the genes we found are in regions of the genome previously suspected but not confirmed for a link to body mass index and obesity," says co-lead investigator Andrew Feinberg, M.D., M.P.H., King Fahd Professor of Molecular Medicine and director of the Center for Epigenetics at Johns Hopkins' Institute for Basic Biomedical Sciences. "Meanwhile, others were a surprise, such as one known to be associated with foraging behavior in hungry worms."
Starting with DNA samples extracted from Icelanders' white blood cells banked in 1991 and 2002 by scientists there as part of the AGES-Reykjavik study of individuals in the general population, the Hopkins team used a customized, genome-wide profiling method dubbed CHARM (comprehensive high-throughput arrays for relative methylation) to look for regions that were the most variable, all chemically marked by DNA methylation.
"Epigenetics has given us 13 exciting new leads to variability in body mass and obesity," says co-lead investigator M. Daniele Fallin, Ph.D., associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "The team's success suggests a new epigenetic strategy for identifying those at risk for many common diseases, and for possible new prevention methods and therapies."
Curious to know if these signatures were linked to obesity-related disease, the researchers analyzed them in relation to each person's body mass index -- a measure of one's weight relative to height. BMI was chosen, Feinberg says, because a high BMI predicts risk for many common diseases in the general population.
"What we accomplished is a small proof-of-principle study that we think is just the tip of the iceberg in using epigenetics to expand our knowledge of new markers for many common diseases and opening the door for personalized epigenetic medicine," Feinberg says.
"BMI is just a starting point for us," agrees Rafael Irizarry, Ph.D., a professor of biostatistics and co-author of the report. "We want to use the same method to look for genes associated with autism, bipolar disease and variations in aging."