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.
However, some cats may attain the age of 21 years or more. By comparison, the average life expectancy of humans in the United States at birth in 2014 was 79.56 years. The oldest cat ever recorded was Creme Puff, who died in 2005, aged 38 years, 3 days. Aging in dogs.