Sickle cell disease causes kidney damage that gets worse with increasing age, leading to chronic kidney disease and kidney failure in nearly one third of patients with sickle cell disease. Some patients develop kidney damage at a young age and others show mild kidney damage at older ages. We do not know the natural progression of kidney damage in sickle cell disease patients, nor do we know who is more prone to develop severe kidney damage. Therefore, currently, there are no preventative measures or treatments for sickle cell related kidney disease. The purpose of this research study is to collect data that will help in assessing the progression of kidney damage in sickle cell disease, develop novel urine and blood tests that can predict kidney damage early, and developing treatment ideas for intervention and prevention of kidney damage that eventually leads to kidney failure.