Pretty early on it was found that some forms of obesity were worse than others. If you tend to get fat deposits around the waist in the classic beer belly, then you are more likely to suffer from heart disease.
Our next group of researchers decided to figure out why people store fat differently. They found three genes that seemed to pretty accurately predict where someone's fat deposits will end up. How did they find these genes?
Microarrays. The microarrays they used were a bit different than the one our first group of researchers used. The first group was looking for DNA changes. The second group was looking for differences in how genes are expressed. What does this mean?
Genes are simply recipes for making certain proteins. And these proteins are the cell's worker bees. They do most of the work based on instructions from the DNA.
Now, having a recipe doesn't give you a meal. You need to read the recipe, collect the ingredients, and follow the instructions. Genes are like this too.
If a cell doesn't read a gene, then it doesn't make that gene's protein. It is like not having the gene. So a gene can be on (read by the cell) or off (not read).
Like a recipe, a gene can also make more or less protein (sort of like the Bisquick box that has recipes for making different amounts of pancakes). How much protein gets made depends on the exact recipe a person has (their DNA sequence) and/or how much of the ingredients are left.
So our second set of researchers wanted to know which genes are turned on in different fat deposits. And to what level. They started out looking in mice.
Specifically, the researchers looked at 6200 genes in fat deposits from two different places in the mice. They found around 7 genes that were turned on to different levels in the two fat deposits.
They then did further testing and narrowed the genes down to five. Next they moved on to people. In people they found that how much three of these genes were turned on did a remarkable job of predicting where fat would be stored in a person.
This is all cool but pretty academic at this point. Yes it is interesting to know why some people are shaped the way they are but can knowing this help them? Maybe, maybe not.
Remember, people who tend to store their fat around their waists are at a higher risk for various diseases. Let's say one of these genes is the reason. Then, if we can find a way to affect the gene then we may be able to find a medicine to affect the gene.
It is important to note that there is no link here between disease and these genes. These genes may just be a side effect of other genes. But even if that is true, it is a good clue for finding the real culprit genes.