Addendum

DNA Solutions just called with the results of the boys' test. Alex and Zach are identical! While this doesn't actually change anything, it's nice to be sure when people ask us. It also is good to know from a medical standpoint, although if some condition were to develop where one boy would need to help the other, a more in-depth DNA test would probably be done. We just had 8 markers tested.

So even though we have Pumpkin Head and Skinny Head running around, that's most likely the result of their mild Twin-to-Twin Transfusion Syndrome. Environmental factors will always play a part to make them unique in their own ways. This also means that the chance of having another set of twins is as low as it was the first time, should we ever decide to expand our already pretty full family. It's not something that's hereditary through me.