CH kitten

Hello, I am looking at cats and came aross a 5 month old boy that has a very mild case of CH, and a very tiny girl kitten that has a VERY severe case. Having recently lost my first cat to a fatal illness, I want to make sure CH only effects mobility and is not linked to any other illness. Also, I want to make sure cats with CH do not require expensive meds or treatments. The boy cat, Kenny Dance, lurches a bit when he gets excited, but otherwise he was active and got around just fine. He flipped his bed over onto himself, it was funny. The little girl meowed at me when I went to put her back, which made me want to take her right that second, but she's too small.

Can you tell us, who dont know, what CH is? I searched for in on the web, but nothing came up...