your son have sickle son disease. permanent treatment of it is very difficult and costly. it required bone marrow transplant and its very tidy and difficult. so you required symptomatic treatment. many sickle cell disease children live long life. best treatment is oxygenation at the time of crisis or and symptoms. because in this disease the rbc becomes sickles shaped when deoxygenated, and sickle like rbc s cant pass through capillary network easily and it will create some crisis and other problems. so oxygen is the main treatment, moreover you need long term folic acid treatment. it is helpful.