Blood transfusions can interfere with hemoglobin variant testing. A patient should wait several months after a transfusion before having testing done. However, in patients with sickle cell disease, the test may be done after a transfusion to determine if enough normal hemoglobin has been given to reduce the risk of damage from sickling of red blood cells.
Since newborn screening programs have started including testing for hemoglobin variants, they have uncovered thousands of children who are carriers. This is due to new technology, not to an increased prevalence of the gene mutations. The health of children is not affected by having single changed gene copies, but the availability of this new information has greatly increased the need for information about hemoglobin variants and their inheritance.
