Genetics of monogenic obesity 1

Published on December 31, 2015   31 min

Other Talks in the Series: Obesity: Science, Medicine and Society

Other Talks in the Series: Molecular Genetics of Human Disease

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My name is Johannes Hebebrand, together with Anke Hinney, we are going to present a talk titled Genetics of Monogenic Obesity. Anke is a molecular geneticist who's been working together with me for over the past 20 years and I'm myself a child and adolescent psychiatrist with training in human genetics. And we have been working on the topic of obesity but also on eating disorders which I will briefly also dwell on. Now the pleasure to introduce you to the genetics of monogenic obesity.
There have been numerous studies pertaining to formal genetic aspects of body weight regulation. These studies have focused on twins but also on adoption studies. Obviously, adoption studies are not that common, but nevertheless there are quite a few. The overall picture of these studies is that genetic factors play a prominent role for development of obesity, but also for body weight regulation in general. Actually most studies have revealed heritability estimates that exceed 50 percent. Some experts think the rate is somewhat lower, other studies have come up with higher rates. But the general consensus is around 50 percent of the variance explained by genetic factors.
If we look into the genetics or molecular genetics of obesity, now we're trying to pinpoint genes that are involved in body weight regulation. It is very important to point out that obviously body weight regulation is something very complex. And this slide actually illustrates that many different central mechanisms are related to our eating behavior but also related to body weight regulation in general. So there are many different aspects that come into this. Just to point out a few, you have a homeostatic drive, you obviously taste, smell food, you learn what tastes you like, what tastes you dislike. There is a memory for this unique hormonal input and neural input from the gut into the brain once you have ingested food. So there are many, many different aspects and this tells you immediately that this is a complex phenotype with most likely very many different factors involved, obviously not only genetic but also environmental factors.