How does this result tell if my son is SS or AS

Patient: My 2 year old son was recently diagnosed with sickle cell anemia. This prompted the necessity for all the family to do hemoglobin electrocytises. This test revealed that my husband, two of our kids and me are all carriers of the hbs. Now my question is what is the level of severity of my son’s condition if his result shows 44% of HBA1 and 52% of HBS and 2.5 of HBA2 does this mean he is a carrier of 2 pairs of our ss genes or just one like his 2 other brothers. THanks, Zainab

Doctor: In order to be HbSS ie homozygous( contains both the pairs of genes ) one needs to have HbS of more than 80%. Since your son has HbS of 52% and HbA1 of 44% means that he is a heterozygote ie has only one pair of the genes. Thus he will be normal most of his life expect when and if he is exposed to conditions which lead to hypoxia ( ie decreased oxygen carrying capacity of the blood) . I hope this helps.