What is fd6 & is it bad for your health?

Do you mean : G6pd? I really don't know what you mean by fd6 as a condition. Fd6 monoclonal antibody is use in detecting certain genetic diseases. G6pd is a hereditary disease in which rbc's breakdown when the body is exposed to certain drugs or stress of infection. Patient mostly asymptomatic. When exposed the hemolysis will cause dark urine, tachycardia, fatigue, shortness of breath. Most pat recover well.