If both beta globin genes code for the sickle protein, the person has sickle cell disease. Sickle cell disease is determined at conception, when a person acquires his/her genes from the parents. Sickle cell disease cannot be caught, acquired, or otherwise transmitted.
For every year of the cat's life after age 2, one cat year equals approximately 4 human years. This is based on how cats mature - for example at around 10 - 11 human years most cats start to slow down quite a lot... This is when they're getting to about 60 years old in Kitty terms.
The oldest cat recorded by the Guinness Book of World Records was one called Creme Puff, who was 38 when he died, and there are stories of others living even longer lives than this. This is quite unusual though, as an average cat life span is around 15-20 years. The kitten stage of a cat's life lasts from birth until puberty, which occurs from between six to eight months old. He's then considered a young adult up to the age of six.