Explain how a hereditary disease can be corrected. Give an example of first successful attempt made towards correction of such diseases.

Hereditary diseases can be corrected by Gene Therapy.

In this process the corrected genes are inserted into the individual’s cells and tissues in embryonic stage so that normal functioning may be regained before birth.

The first clinical case of gene therapy was in 1990 , a case of a 4 year old girl diagnosed with Adenosine Deaminase (ADA) Deficiency. For her treatment the patient’s lymphocytes are taken and cultured outside the body. Then a functional ADA cDNA is introduced in them and then the lymphocytes are placed back inside the body leading to be a non permanent but long term cure. But if the gene is isolated from marrow and then corrected then it would be a permanent cure.