There is some support for the hypothesis that Actn2 is downstream of a polymorphism in the Hars2 region. But again, due to the 10 to 20 Mb precision of the mapping data, this relation could be generated by a large number of other polymorphisms close to Hars2. In the absence of a biological connection between Actn2 and Hars2 we have a weak hypothesis. If there were a plausible functional connection between the two genes, then this hypothesis could be quickly upgraded.