In breeding can lead to multiple issues, whether they are physical or internal issues. For instance, I have an inbred Bearded Dragon that I rescued a year ago. He hasn't grown since I've rescued him, and more than likely will never be more than the 5 inches he is. He's probably the same size as a 4-5 month old Bearded Dragon. He has a twisted tail towards the tip as well from being inbred.
Here is an attached photograph of him.