Sickle cell disease is a blood disorder that's inherited — meaning it's passed down from parents to their children. Babies are born with sickle cell disease when they inherit two abnormal genes. Sickle cell disease is not contagious , so you can't catch it from someone else or pass it to another person like a cold or an infection. People with sickle cell disease have it because they inherited two sickle cell genes, one from each parent.