Should we stop talking about heritability in 2014?

Genetic epidemiology. Long before the first epilepsy gene was discovered, clinicians and researchers were wondering about a genetic contribution to epilepsy. Some epilepsy syndrome were found to run in families in an autosomal dominant or recessive pattern. In other epilepsies, there was an obvious excess of affected family members in the immediate or extended family. And this is how we got stuck with the concept of heritability. Let’s review the perils and pitfalls of heritability and ask the question whether we should retire this concept in the current era of genomic medicine. Continue reading

The genetic architecture toolkit – modeling polygenic disease with rare variants

Architecture. Even though we often write about novel gene findings in the epilepsies, we assume that most epilepsies are complex genetic or polygenic. Polygenic inheritance suggests the genetic architecture is composed of multiple interacting genetic risk factors, each contributing a small proportion to the disease risk. However, when using the phrase genetic architecture, sometimes I am not quite sure what I actually mean by this. For example, how many genes are needed? This is why I wanted to build a model genetic architecture and explore what happens if we build a genetic disease solely from rare risk variants. Follow me to a brief back-of-the-envelope calculation of how this might work.

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