Gene Therapy



- Very effective against diseases and gene abnormalities.







There are genetic engineering techniques applied in Gene therapy. Gene therapy is the genetic engineering of humans by replacing defective human genes with functional copies.


The Effects of Gene Therapy

By using gene therapy to modify cell, the scientists believe that we may be able to cure or improve the conditions of genetic disorders and prevent its continuity. With the defective gene modified by a healthy gene,
Different types of gene therapy (different ways of approach)
Germ line gene therapy
- In this therapy, a patient’s sperm cells or eggs are introduced to functional genes, thus allowing the change in the genome to be passed on to the next generation. This is a relatively new approach in which the researchers believe will be effective solution to genetic disorders.
Somatic gene therapy
- This therapy is a therapy in which a functional gene is inserted into a random cell in the patients body, with its effects confined to the respective patient.
- Inactivation of a mutated gene
- Replacement of mutated gene with a healthy one
- Introduction of a new gene



Advantages
Disadvantages
Gives the opportunity to someone who is born having a genetic disease (cancer) of having a normal life
If unborn has defective gene when being tested, this may increase number of abortions. Creates some more ethical problems.
Allows someone who is born with a genetic disease the opportunity of replacing a non-functional gene with a functional one
The idea of changing of genes can result too much of an impact to some individuals and this may reduce chance of having gene therapy.
Cancer patients can be benefited of this by the insertion of altered vectors into the genome
There are small possibilities that gene therapy can have some problems and this may change the opinion of many persons.


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Gene Therapy in Color Blindness

Gene therapy for color blindness is an experimental gene therapy aiming to convert colorblind individuals to trichromats (three channels for color) by introducing a photopigment gene that they lack. Partial color blindness is considered only a disability and is controversial whether it is even a disorder. It is a condition that affects many people, especially males. Complete color blindness, or Achromatopsia, is very rare but more severe. While never demonstrated in humans, animal studies have shown that it is possible to confer color vision by injecting a gene of the missing photopigment using gene therapy.

Color Blindness:
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The retina of the human eye contains photoreceptive cells called cones that allow color vision in you eyes. The three types of cones are designated L, M, and S cones, and each type is sensitive to a certain range of wavelength of light depending on what photopigment it contains.

Motivation:

The goal of the gene therapy is to make some of the cones in the retina of a Dichromatic (color blind) individual to express the missing photopigment. Although partial color blindness is considered to be a soft disability and even an advantage under certain circumstances (like camouflaged objects), it can create challenges for certain jobs such as driving or piloting an aircraft. Because only a single gene codes for a photopigment and the gene is only expressed in the retina, it is a relatively easy condition to treat using gene therapy compared to other genetic diseases.

The main challenge of this gene therapy is that if not treated carefully it can result in total blindness, or Achromatopsia.


Websites used:

- thrichromacy. N.p., n.d. Web. 19 Nov. 2010. <http://en.wikipedia.org/‌wiki/‌Trichromacy>.

- Gene Therapy in Color Blindness. N.p., n.d. Web. 19 Nov. 2010. <http://en.wikipedia.org/‌wiki/‌Gene_therapy_for_color_blindness>.

Images:
http://www.giantbomb.com/color-blindness/92-2418/
http://www.fz-juelich.de/isb/isb-1/Achromatopsia/