The correct answer is Option (2)- The thalassemia is a quantitative problem of synthesizing too few globin molecules while the sickle cell anaemia is the qualitative problem of synthesising an incorrectly functioning globin.
- Thalassemia is an autosome-linked recessive blood disease transmitted from parents to the offspring when both the partners are unaffected carrier for the gene (or heterozygous). The defect could be due to either mutation or deletion which ultimately results in reduced rate of synthesis of one of the globin chains (α and β chains) that make up haemoglobin. This causes the formation of abnormal haemoglobin molecules resulting into anaemia which is characteristic of the disease.
- Thalassemia can be classified according to which chain of the haemoglobin molecule is affected. In α Thalassemia, production of α globin chain is affected while in β Thalassemia, production of β globin chain is affected.
- α Thalassemia is controlled by two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent and it is observed due to mutation or deletion of one or more of the four genes. The more genes affected, the less alpha globin molecules produced.
- While β Thalassemia is controlled by a single gene HBB on chromosome 11 of each parent and occurs due to mutation of one or both the genes.
- Thalassemia differs from sickle-cell anaemia in that the former is a quantitative problem of synthesising too few globin molecules while the latter is a qualitative problem of synthesising an incorrectly functioning globin.
- Sickle cell trait is a blood condition that runs in some families. People with it have one copy of the "sickle cell gene," but they don't have sickle cell disease. If a mosquito carrying the malaria germ bites someone with sickle cell trait, the person isn't as likely to get as sick as other people. That’s because people with sickle cell trait have red blood cells that make it hard for the malaria germ to grow.
- Some research has suggested that people with thalassemia are less likely to suffer from malaria due to a protective effect of the condition. It appears that smaller quantities of hemoglobin in more cells, which is a distinctive characteristic of thalassemia, may offer an advantage against malaria. According to the research, children with mild alpha-thalassemia have natural protection against the anemia associated with malaria. For severe cases of malaria, an individual can lose 30-50% of total RBCs and lead to anemia in the blood. However, children with alpha-thalassemia tended to recover more easily after experiencing a malaria attack.
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