I’ve written before about a pattern emerging from genome-wide association studies–genes in which mutations cause rare extreme forms of a phenotype often harbor common variation that influence natural, non-disease variation in that same phenotype. A pair of new studies on variation in cardiac repolarization (summarized here) provide an additional example of this pattern.
It’s worth noting that this was something of an obvious hypothesis–candidate gene association studies often targeted gene known to cause Mendelian disorders when mutated. In retrospect, the reason these studies were often inconclusive was a simple lack of power.