please before adopting any manx have them fully checked by your vet and wait until they are at least 4 months old. we adopted a manx kitten a few months ago, and unfortunately for us this sweet kitten had a genetic disease that is specific to the manx breed- manx syndrome. she got very sick very quickly and it was heartbreaking to myself and my family, especially my son because we had to finally euthanize her due to repeated infections among other major problems. we tried to keep her as best we could, but it wasn't cheap to constantly medicate her and it wasn't helping either. it is really quite sad to euthanize a 5 month old kitten, really it was heartbreaking and my son still gets sad thinking about what we and our kitten went thru- he was very attached to her...
there are things you can do if you want a manx kitten and ways that a breeder can take care to ensure that adopting families can have the healthiest kittens they can. one is to wait until at least 4 months for the kitten to be adopted. this syndrome usually doesn't even show up until around 3-4 months or even later and then it begins quite gradually. if a breeder keeps the kittens for a time, they (esp. being familiar with symptoms vs breed traits

)can make sure that the kittens are healthy.
i hate to take over the thread but i wanted to share our experience and make sure that anyone who would adopt these wonderful cats get a bit informed- and avoid any problems and sad stories in the future
oh, and here's a link to some manx info- including a bit about the disease.
http://fanciers.com/breed-faqs/manx-faq.html