Dogs with chondrodysplasia have a rare genetic mutation that may also be related to some forms of dwarfism in people.
Source: Parker HG, VonHoldt BM, Quignon P, et al. An expressed Fgf4 retrogene is associated with breed-defining chondrodysplasia in domestic dogs.
Science
2009;325(5943):995-998. [Epub 2009 Jul 16.]