Spinal Muscular Atrophy in Maine Coon Cats(SMA)


SMA is an inherited disorder affecting the skeletal muscles of the trunk and limbs. Loss of neurons in the first few months of life leads to muscle weakness and atrophy that first becomes apparent at 3-4 months of age. Affected kittens develop an odd gait with a sway of the hindquarters and stand with the hocks nearly touching. They may also stand with toes out in the front. By 5-6 months of age they are too weak in the hindquarters to readily jump up on furniture and often have a clumsy landing when jumping down. The long hair Maine Coon may hide it, but careful feeling of the limbs will reveal reduced muscle mass. Affected kittens are not in pain, they eat and play avidly, they are not incontinent, and most live very comfortably as indoor cats for many years. Known affected kittens have occurred in breeding programs across the United States, and, in retrospect, likely carriers have been exported widely.

Onset of clinical signs is observed between 15 and 17 weeks of age. Initial abnormalities are hind limb weakness and a fine generalized tremor. Affected kittens lose the ability to jump strongly by five months and walk thereafter with a sway of the hindquarters. Abnormal sensitivity to touch over the back, exercise intolerance, and laboured breathing are variably observed. After an initial period of rapid loss of function, the progression of the disorder slows or plateaus with variable muscle atrophy, weakness and mobility.

There is a DNA test available to identify the gene mutation that causes SMA in Maine Coons. Using this test it will be possible to identify the gene mutation in cats that are affected with SMA or carriers of SMA and to identify those cats that are genetically normal for this disease.


ALL OUR BREEDING CATS ARE SMA TESTED NORMAL (DNA).


Interpretation of test results:

A Normal spinal muscular atrophy genetic test result means that the cat does not have the known genetic mutation causing spinal muscular atrophy in Maine Coon cats.

A Carrier spinal muscular atrophy genetic test result means that the cat has one copy of the spinal muscular atrophy mutation. The cat will not have spinal muscular atrophy, but may pass the mutation to their offspring.

An Affected spinal muscular atrophy genetic test result means that the cat has two copies of the spinal muscular atrophy mutation. The cat will have spinal muscular atrophy.