An international team of scientists has identified six new obesity genes that are active in brain cells.
In addition to the FTO and MC4R genes already known, it was now possible for six more obesity genes to be identified: TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2, and NEGR1.
The gene expression analyses have shown that all six genes are active in brain cells.
In the study involving 59,000 participants conducted by GIANT consortium, the German researchers believe that these newly discovered genes for obesity have a neural effect.
"Definitely, the two main causes for obesity are poor nutrition and lack of physical activity. But the biology of these genes suggests genetic factors underlying the different reaction of people to lifestyle and environmental conditions," said Prof. H. Erich Wichmann and Dr. Iris Heid from the Helmholtz Zentrum München, Institute of Epidemiology.
Except for SH2B1 gene, which plays a role in the leptin signalling and thus in the regulation of appetite, none of the other five genes was hitherto discussed as obesity genes.
"The purely statistical approach of the genome-wide association analysis can depict new aspects of the biology of weight regulation, which were previously unanticipated," the researchers added.