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Genetic Testing and Screening

explanatory Essay
2689 words
2689 words
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Its no accident that off-spring resemble their parents. Deoxyribonucleic acid or DNA, located within each cell nucleus is a special chemical, that determines our genetic inheritance in a very orderly way. Under the microscope DNA looks like a mass of tangled threads which consist of tiny subunits called genes. Genes carry instructions, sometimes called the blueprint of life, for various characters like hair color, height, eye color. Our genes are received from both mother and father, half from each. Genes instruct our bodies to make proteins - which determines the shape and function of each cell. Each gene controls the production of a particular protein. Genes produce millions of different proteins through different arrangements of just four simple molecules the nucleotides - adenine (A), cytosine (C), thymine (T), and guanine (G). These A,C,T and G's are like letters of the alphabet - their order "spells" out the language of life.

The Human Genome Project (HGP) was proposed in the 1980s and was formally initiated in 1990. Its major aims are to map and determine the chemical sequences of the three billion nucleotide base pairs that comprise the human genome. Completion of the HGP in the projected 15 years will provide a source book for biology and medicine. The Human Genome Diversity Project (HGDP) complements the HGP by examining the genomic variation of the human species, through analysis of DNA from populations, families and individuals worldwide.

There are many different techniques involved in gene screening. With the start of the Human Genome Mapping Project some of these techniques have been altered to speed up the screening process. Examples of these techniques include PCR (polymerize chain reaction), RFLP's (restricti...

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...WWW: http://www.torontobiotech.org/factsheets/series1_02.htm

2. Encyclopaedia Britannica. Obtained from WWW : http://search.eb.com/bol/search?Dbase=Ar

3. Genetic Screening and Counseling. Obtained from WWW : http://www.gaucher.org.uk/genetic.htm

4. Genetic Screening and Ethics an Overview Obtained from WWW : http://www.woodrow.org/teachers/bi/1992/gen_screen1.html

5. Genetic Testing and Genetic Screening. Obtained from WWW : http://www.georgetown.edu/research/nrcbl/scopenotes/sn22.htm

6. The Application of Human Genetic Research. Obtained from WWW : http://www.bioportfolio.com/efb3.htm#hgp

7. Marshall, Eliot. 1999. Beryllium Screening Raises Ethical Issues. Science. 285(5425): pp178-179.

8. Blatt, Robin JR."An Overview of genetic screening and diagnostic Tests in Health Care". Obtained from the WWW: http://www.geneletter.org/0996/screening.htm

In this essay, the author

  • Explains that dna determines our genetic inheritance in a very orderly way. genes instruct our bodies to make proteins.
  • Explains that the human genome project (hgp) was proposed in the 1980s and was formally initiated in 1990. it aims to map and determine the chemical sequences of the three billion nucleotide base pairs that comprise the human genome.
  • Explains how pcr, rflp, and cloning have been altered to speed up gene screening. rapd, gawts and other techniques are being utilized in the mapping and sequencing of the human genome.
  • Explains that genetic screening is a process to analyze blood or skin for the systematic search for persons with genotypes in defined populations and serves as an important tool of modern preventive medicine.
  • Explains that markers have already been found for various diseases such as huntington's disease, cystic fibrosis, duchenne muscular dystrophy, hemophilia and thalassaemia, and some rare cancers.
  • Explains that genetic screening is currently available for the following conditions: sex, abnormal chromosome number, early onset conditions, susceptibility to hypercholesterol, alcoholism, carriers of recessive genes.
  • Explains that screening is carried out to discover undiagnosed sufferers or those with genetic markers for the disease.
  • Explains that types 2 and 3 are so rare that discovery usually only takes place once a child has already been born with the disorder. in subsequent pregnancies, the fetus can be tested early.
  • Explains that in type 1, if both parents have disease, the child must inherit the disease or the genetic markers for it.
  • Explains that if both parents are carriers, there is a one in four chance in each pregnancy that the child will have the disease or the genetic markers for it.
  • Explains that screening of undiagnosed people who have the disease, or have genetic markers for it, and those who are carriers, is highly unlikely due to the rarity of the condition.
  • Explains the two types of genetic screening: presymptomatic screening and carrier screening, which are carried out in healthy individuals where genes are harmful to their future offspring.
  • Explains that prenatal screening is done when a fetus is at risk for various identifiable genetic diseases or traits. newborn screening started in 1960 with the ability to test newborns for phenylketonuria.
  • Explains carrier screening is related to the analysis of individuals with a gene or chromosome abnormality that may cause problems either for offspring or the person screened.
  • Explains that forensic screening seeks to discover a genetic linkage between suspects and evidence discovered in criminal investigations. since dna is unique, many people are reluctant to see such information become part of any national database.
  • Explains that susceptibility screening helps identify workers who may be susceptible to toxic substances in their workplace and may cause future disabilities.
  • Explains that there are different times throughout the life span of a human in which genetic tests, both screening and diagnostic can be preformed.
  • Explains that msafp is a blood-screening test performed at the 16-18 week gestation date and tests for spina bifida.
  • Describes the recommendations of the uk nuffield council on bioethics regarding genetic screening and the social response to these developments.
  • Explains that screening can be used for medical intervention and research, reproductive information, enumeration, monitoring, surveillance, and registries of genetic disease and disability.
  • Explains the committee of ministers of the council of europe's recommendations to allay any future unease.
  • Explains that the danish council of ethics views genetic information as different from other private information since it reveals knowledge not only about an individual, but also the individual's relatives.
  • Concludes that privacy is an explicit constitutional right that includes respect for genetic privacy and is protected by legislation. employers should be prohibited from collecting genetic information.
  • States that the president's commission recommends that information stored in computers be coded and compulsory genetic screening not be justified to create a health gene pool or to reduce health.
  • Opines that genetic screening is an ethical solution to human life. pre-natal diagnosis for a genetic condition is available in the case of diseases like down's syndrome.
  • Opines that there are many issues to be solved before genetic screening is made universal.
  • Cites the toronto biotechnology initiative, encyclopaedia britannica, genetic screening and counseling, gaucher, and woodrow.
  • Explains the importance of genetic testing and genetic screening in health care, and the application of human genetic research.
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