The short legs of dwarf cats are thought to be due to pseudoachondroplasia a type of short-limb dwarfism. It affect people as well. The prefix “pseudo” is used as the affects of this genetic mutation is not the same as achondroplasia dwarfism. The difference (as I mention on the dwarf cat health issues page) is that while pseudoachondroplasia is characterised by short limbs and a normal head, achondroplastic dwarfism is characterised by short legs and an enlarged head.
I don’t know how settled the assessment of the genetic mutation is dwarf cats is. But I do know that recent research has uncovered the cause of the canine equivalent of the dwarf cat, the dachshund.
Research indicates that the short legs of the dachshund (a dog with a normal body and head like dwarf cats and short legs) are due to the mutation, thousands of years ago, of a single gene.
The American National Human Genome Research Institute discovered that all short-legged purebred dogs carried an extra copy of a gene that codes for a “growth-promoting protein called fibroblast growth factor 4 (FGF4)”. This gene is thought to be, “a retrogene that was inserted into the dog genome some time after the ancestor of modern dog breeds diverged from wolves.”
Its presence results in the overproduction of the FGF4 protein, which is believed to switch on growth receptors at the wrong time during foetal development. This in turn causes the legs to be short and out of proportion.
The question I have is whether this research has any bearing on the creation of the short legs of dwarf cats? Answers would be welcome and can be submitted, please, on a form at the base of the Dwarf Cats and Miniature Cats page.