I'm glad basketball is a limited contact sport because I'm not good at it and I'm brittle boned
DO you play basketball now?
Nah, I do brazillian jiu jitsu now, it's a full contact sport, my bones are much less brittle now
Oh yes, I would say Jiu Jitsu is much more contact then basketball. 
BJJ is a combat sport with high level problem solving and dire physical consequences
Is it similar to Karate or Tae Kwon Do?
It is more of a ground fighting sport, centered on take-downs and following the movement of your opponent. 
Is it like Mixed Martial Arts?
It is! It is very popular in MMA and UFC as well as other combat sports that allow striking and grappling