A cat that is having difficulty breathing or has loss of function of hind or front limbs requires veterinary care as soon as possible. (thedrakecenter.com)
Additionally, her shoulders move as though her entire front limbs are intact and touching the ground when she walks. (patrickmahaney.com)
In affected cats, signs are usually first evident by the time kittens are 1 - 5 months of age, and will progress over time to the point where there will be weakness (first of the hind limbs then front limbs as well), depression, seizures and eventually the kittens will die, typically at 8 - 10 months of age. (icatcare.org)