Which type of anemia is characterized by a genetic disorder leading to abnormal hemoglobin?

Sickle cell anemia is a specific type of anemia that results from a genetic mutation affecting the structure of hemoglobin. In this condition, the hemoglobin molecule is altered, leading to the production of hemoglobin S instead of the normal hemoglobin A. This abnormal hemoglobin causes red blood cells to form a characteristic sickle, or crescent, shape under low oxygen conditions. These sickle-shaped cells are more rigid and can obstruct blood flow, leading to pain and various complications. The genetic nature of this disorder means it is inherited in an autosomal recessive manner, requiring that both parents pass on the mutated gene for a child to be affected. This distinguishes sickle cell anemia from others, as the other types of anemia listed are primarily due to nutrient deficiencies, bone marrow failure, or destruction of red blood cells rather than a direct alteration of the hemoglobin structure itself.