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.
For every year thereafter, each cat year is worth about four human years. Using this formula, a ten-year-old cat is similar age wise to a 53-year-old person, a 12-year-old cat to a 61-year-old person, and a 15-year-old cat to a person of 73. Advancing age is not a disease. Aging is a natural process.