Genetic Screening

Authors Avatar

The Application of DNA Technology in the Diagnosis and Treatment of Disease

 This essay is going to look at genetic engineering and genetic screening. The first section will focus on what each of these things are and how they are used in the diagnosis and treatment of diseases. The second section will concentrate on the use of both the nuchal translucency scan and the Guthrie test. The third section will talk about the application of genetic engineering in the production of insulin, and the final section will look at the ethical issues raised by genetic engineering.

 There are many different forms of genetic engineering, for example stem cell, which is the process of removing unused cells from embryos which are then produced into tissue. This is a process that is still being researched and could eventually treat or quash many diseases and conditions.

 The first step is to insert a short piece of foreign DNA into a host organism. This is called gene splicing. For example to insert a piece of DNA from a human into bacterium, you have to break open the ring of DNA from a bacterial plasmid and insert into the human DNA. For the gene splicing to take place it relies on a group of enzymes known as restriction endonticleases. These enzymes will cut the host organism at a specific site which is determined by the bases sequence in that region. It will also cut foreign DNA where there is an identical base sequence. The two cuts will be made of two slightly different points. This means that at each end of the foreign DNA there are sticky ends. This means that there is a row of unpaired bases which will match with the base at each end of the opened host cell. If the conditions are right the unpaired bases and the plasmid will join up, incorporating the foreign DNA into the host cell. This is bonded securely by an enzyme called DNA ligase. The foreign DNA will then be replicated every time the cell divides. There is another enzymes used in genetic engineering called reverse transcriptase. This enzyme produces DNA using messenger RNA as a substrate. This is used when extracting insulin from the human pancreas. Reverse transcriptase can be used to make single strands of DNA called complementary DNA. This can be made into double stranded DNA using an enzyme called DNA polymerase.

Join now!

Genetic screening is used to detect certain conditions in different groups of people or in a population of people. This is done when there is no previous history of a condition. There are many different ways in which screening is carried out, such as blood tests, ultrasounds and gene mutations which can lead to disease and genetic conditions, conditions such as Down’s Syndrome, Sickle cell and Cystic Fibrosis Some tests will be highly prognostic but others will give a result that can tell a single person how much of a risk they are compared to the population.  Genetic screening test ...

This is a preview of the whole essay