Question

How can mutation cause disease? What is an example of it?

Answer 1

Ans.

• A permanent alteration of DNA sequence of a gene, in a way that the sequence is different then the normal sequence, is known as gene mutation.
• Effect of mutation on DNA can range a from single gene to multiple genes of a large chromosomal segments.
• There are two calsses of gene mutations;

1. Hereditary mutations - that are being inherited from the parents and can be found throughout the entire life of a person.
2. Acquired (or somatic) mutations - that can take place at a certain point of a person's life and occurs only in several cells of the body.

• Each cell depends upon numerous proteins in order to function in a correct way.
• Many times mutations in the proteins can affect the proper working of these protein molecules in multiple ways or trigger the synthesis of faulty proteins with abnormal functionality.
• Thus, through an alteration in the instruction of a gene for the synthesis of a particular protein, a mutation may lead to synthesis of a malfunction protein or absence of a protein.
• Therefore, through alteration of a protein which have a critical function in body, a mutation can result in the disruption of a normal process in body or may cause a disease.
• A disease resulting from the mutation of one or more gene is called as a genetic disorder.
• According to several scientists, there is approx. 5-10% of deadly mutations in an individual body which, however, do not manifest normally.
• An example of a disease resulting from mutation is sickle cell anaemia.
• It is a common genetic disease among African people in which the shape of red blood cell becomes sickle shaped.
• This disease result from a point mutation, a single nucleotide change in the gene for hemoglobin.
• Such mutation lead to the distortation of red blood cells shape to sickle shape upon lack of oxygen.
• These sickle shaped red blood cells then accumulate in the capillaries, thereby hampering the circulation of blood.