Genetics of Binge Drinking

There is an interesting article that just came out in PNAS by Prof. Gunter Schumann. To the BBC he states:

We now understand the chain of action: how our genes shape this function in our brains and how that, in turn, leads to human behaviour.We found that the RASGRF-2 gene plays a crucial role in controlling how alcohol stimulates the brain to release dopamine, and hence trigger the feeling of reward. So, if people have a genetic variation of the RASGRF-2 gene, alcohol gives them a stronger sense of reward, making them more likely to be heavy drinkers. (source)

And the BBC article continues:

He said more work was needed to prove this theory - the study only looked at young teenage boys, making it difficult to assess a link with long-term drinking patterns.

It is a preliminary association (ie the study design was not explicit for the finding they made), though the functional work (animal model) looks promising.

In my own family history there is strong evidence of alcoholism, and binge drinking as well. Findings like these make me want to have my genome sequenced. But other reasons, money being a prohibiting factor anyway, keep me from doing so. Its just cool when we can combine this kind of information to understand our genes.

The Lord of Pleiotropy

My wife and I were talking about missionary work and I said the phrase "He is the Lord of Pleiotropy!" and wanted to share it.

Pleiotropy is a genetics word, or my definition comes from there, meaning a gene that has multiple effects. For instance a gene could effect both the facial structure and mental capacity of an individual.

Anyway, in the context I was referring to with my wife I was making the argument that the purpose of missionary work wasn't just about helping investigators understand baptismal covenants and the Gospel of Jesus Christ. It is also important for the development of the missionaries themselves. We live in a difficult world and having the Gospel from your youth doesn't guarantee lifelong devotion to the covenants essential to endure to the end.

I think the title of "Lord of Pleiotropy" is more universal than just missionary work, our Heavenly Father seems to be able to manage a complex interaction of promises and purposes essential for His work. Another example is the scriptures. It seems every time I read them they were inspired for just that moment in my life.

Big Cats and Genetics

My family went to the zoo on Friday and saw the elusive snow leopard. Such a beautiful creature. My wife goes regularly and said the most she usually sees is a tail or spine. We got to see much more when I went, probably due to the late time of our visit. The leopardess looked pretty hungry or desperate to have her sick cubs:

Courtesy of my wife.

This morning I was reading the science page of The New York Times and came across an article about a different big cat, the cheetah. Dr. Stephen O'Brien, now of St. Petersburg State University in Russia and formally of the NIH National Cancer Institute, and some of his colleagues have figured out the genetic variant that changes the type of spotting pattern in different cheetahs:

The one on the right is called a king cheetah. This same gene, Taqpep, is also involved in tabby patterns of domestic cats. Overall pretty cool, and these types of discoveries are helpful in our understanding some questions in evolutionary genetics.

This gene is one of large effect. "Large effect" means that the genetic variant has a direct consequence on the appearance (phenotype). When people think of genetics this is usually the type of variation they are familiar with. Eye color (found in HERC2), hair color (red comes from MC1R), and others, but it turns out that most phenotypes are not derived from genetic variation of large effect, especially for ones of primary interest to us, such as diseases like obesity or autism. They call these latter type of traits complex phenotypes because they usually involve many genes of small effects.

Height is a good example of a complex trait because we know genetics contributes significantly to variation in height (nutrition is important as well). However, height is a composite of many different aspects of our bodies: the length of our necks, the length of our torso, the length of our femur, and so on. In other words height represents an amalgamation of genetics acting on multiple traits all with a much smaller effect. Only when taken together do we see the larger change.

I have been thinking a lot about the genetics of complex diseases/traits and how we may best understand them. I mention it here to introduce the topic, which I will hopefully talk more about soon.