" A groups of genetic disorders of hemoglobin synethesis which result from a defective rate of synthesis of one or more of the globin chains, but there is no defect in the amino acid structure of globin chains.

Correct option is B

Thalassemias are genetic blood disorders characterized by the reduced or absent synthesis of one of the globin chains that make up hemoglobin. This imbalance leads to ineffective erythropoiesis and anemia. Importantly, in thalassemia, there is no defect in the amino acid sequence of the globin chains themselves; rather, the issue lies in the rate of synthesis of the globin proteins, particularly either the alpha or beta chains, leading to alpha-thalassemia or beta-thalassemia​​
· In beta-thalassemia, there is reduced synthesis of the beta-globin chains.
· In alpha-thalassemia, there is reduced synthesis of the alpha-globin chains.
The result is anemia due to the abnormal formation of hemoglobin and the premature destruction of red blood cells.
Information Booster:
Thalassemia is a hereditary condition commonly seen in regions such as the Mediterranean, the Middle East, South Asia, and Africa. Its severity can range from mild (thalassemia minor) to severe (thalassemia major), depending on whether the person inherits one or two defective genes. Treatment for severe cases may involve regular blood transfusions or bone marrow transplants.
Additional Knowledge:
· (a) Methemoglobinemias: A condition where the hemoglobin is altered such that it cannot bind oxygen properly. It is often caused by exposure to certain chemicals, drugs, or genetic factors, but does not involve abnormal globin synthesis​.
· (c) Agammaglobulinemias: A condition related to the immune system where the body is unable to produce enough antibodies (gamma globulins) due to a defect in B lymphocytes​.
· (d) Aminoaciduria: This refers to the excretion of amino acids in the urine, often due to metabolic disorders affecting amino acid metabolism