What is Sickle-cell disease?
It is a disorder of the hemoglobin due to a genetic defect. If oxygen supply is low the red blood cells containing the abnormal hemoglobin assume a sickle shape. Mutation in a single chormosome produces sickle cell trait where 50% of the hemoglobin or less is abnormal. If both chromosomes are defective sickle cell disease with 80-90% abnormal hemoglobin results.