Question

What are the clinical manifestations of thalassemia?

Answer 1

Hint: Thalassemia is a type of autosomal recessive genetic disorder in which the individual is only affected when both the alleles of the gene are present in homozygous condition. It is a type of blood disease as the synthesis of hemoglobin is affected.

Complete answer:
Thalassemia occurs due to the mutation or deletion of the gene that is responsible for the formation of the globin chains (alpha and beta chains) of the hemoglobin. This affects the rate of synthesis of hemoglobin as well as the hemoglobin formed is abnormal. Such conditions lead to anemia which is the characteristic feature of thalassemia. Thalassemia is of different types depending on the globin chain that is affected. If the alpha-globin chain is affected then the disease is alpha-thalassemia and if the beta-globin chain is affected then it is beta-thalassemia. Clinical manifestations or symptoms of thalassemia include fatigue, weakness, yellowish skin, abnormal swelling, dark urine, etc.

Additional Information:
Hemophilia: It is another blood-related disease which is a sex-linked, recessive disorder. A protein that is part of the blood-clotting cascade is affected which results in ineffective blood clotting. Even a small cut can lead to the death of a person due to non-stop bleeding.
Phenylketonuria: It is a type of autosomal genetic disorder in which the affected individual does not have an enzyme that is required for the metabolism of phenylalanine into tyrosine. Accumulation of phenylalanine results in mental retardation.
Sickle-cell anemia: It is a type of autosomal-linked recessive genetic disorder in which the affected individual has abnormal hemoglobin which is sickle-shaped.

Note:
- A autosomal disorder means that the faulty gene is present on the autosomal chromosomes whereas a sex-linked disorder means that the faulty gene is present on allosome (X and Y) chromosomes.
- Thalassemia is different from sickle cell anemia because thalassemia is a quantitative problem whereas sickle cell anemia is a qualitative problem.
- Alpha-thalassemia genes are present on the 16th chromosome whereas beta-thalassemia genes are present on chromosome 11.