Final answer:
Silent carriers with smaller than normal red blood cells may have microcytic anemias like sickle cell anemia or ß-thalassemia, which impairs the blood's oxygen delivery and can lead to symptoms like fatigue and increased infection risk.
Step-by-step explanation:
When a silent carrier has red blood cells (RBCs) that are smaller than normal, this condition is part of a group of disorders known as microcytic anemias. These disorders are characterized by the production of RBCs that are smaller in size, identified by a low mean corpuscle volume (MCV). Examples of microcytic anemias include sickle cell anemia and ß-thalassemia. Sickle cell anemia often involves RBCs that are crescent-shaped and rigid, leading to blockages in capillaries and a reduced ability to deliver oxygen. ß-thalassemia is caused by a genetic defect that results in reduced levels of hemoglobin and hence a diminished oxygen-carrying capacity. The consequences of these anemias are severe, as they can lead to symptoms like fatigue, weakness, low growth rates, and increased susceptibility to infections due to the overall reduction in oxygen being delivered to body tissues.