Monday, 28 May 2012

PGD- Preimplantation Genetic Diagnosis

By: Theresa Bügler- Student #42908982
P9- Mark Mayhew


Ironically the social driving force behind the need for infertility technologies was the availability of abortions in the late 1960’s. This coupled with the establishment of single parent benefit which occurred in Australia around the same time significantly reduced the availability of babies for adoption and consequently process’s which allowed infertile couples to conceive were in demand.[1]




Enter IVF ! –

First test tube baby Louise Brown was grown in a JAR

Read more: CLICK HERE

On July 25, 1978, Louise Brown, the worlds first ‘test tube’ baby was born in Manchester. Australia followed closely in 1980 with the 4th IVF ( In Vito- fertilization) baby born in Melbourne [2]


As processes became more advanced, procedures such as PGD (Preimplantation Genetic Diagnosis)[3]were established and the age of designer babies was ‘born.’

GENDER CHOICE – A human Right ????

“Woman aborts healthy twin boys
in pursuit of a girl!!”
(Australia 2011)

Read more: CLICK HERE


When determining the social acceptability of gender selection on the grounds of balancing families or individual choice the jury seems to be out with both camps putting forward strong cases. Groups apposed to gender selection state that selecting the sex of a child is detrimental to the parent-child relationship which should be unconditional acceptance. Gender selection may create sexual prejudice especially in cultures where girls are less valued; this will ultimately affect the social structure contributing to a shortage of women for men to partner.  While Sydney IVF’s data contradicted the preference of male babies[4], this has been proved to be the case in China where males are more valued and therefore, female fetuses were aborted as couples were only allowed one child and wished to try again for a boy, currently there 156 boys to every 100 girls[5] in China. This potentially could imbalance the laws of nature.



 
Watch the harvest of the Blastomere



Two cells being harvested from the blastomere




Why Use PDG?

Preimplantation Genetic Diagnosis is available for three major categories of diseases: sex linked diseases, molecular disorders, and chromosomal disorders.
Sex Linked:  PDG can be used to identify the sex of the embryo for sex linked disorders An example of this group is Duchenne muscular dystrophy. Molecular disorders: single gene defects such as cystic fibrosis can be identified.

Chromosomal disorders including translocations, inversions, and chromosome deletions can be detected using Fluorescence In Situ Hybridisation (FISH).  Parents who carry a chromosomal rearrangement / alterations may never successful achieve a viable , often resulting in repeated spontaneous miscarriages as a result of unbalanced chromosomes in the embryo.


For the list of possible diseases identified in PGDClick Here

 

Now let’s make them perfect -->

Designer babies

 

Through a process known as FISH or Fluorescent in-situ Hybridization the nucleus of the cell is exposed, the cells are then dried on a microscope slides and hybridised or bonded with DNA probes. Each of these coloured probes or markers are specific for part of a chromosome, and are labeled with a fluorochrome which makes the chromosomes florescent and the chromosomes including the X and Y chromosomes are able to be identified. [6]

Image showing FISH (Fluorescent in-situ Hybridization)

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References:


[1] BBC News ( July 25,1978). FIRST TEST TUBE BABY BORN  (online) Available:
http://news.bbc.co.uk/onthisday/hi/dates/stories/july/25/newsid_2499000/2499411.stm (Accessed
10.03.12)
[2] The World Today. 22.06.2010. Australia's first IVF baby turns 30. (online) Available: www.abc.net.au%2Fworldtoday%2Fcontent%2F2010%2Fs2933566.htm&ei=wxdkT_n1OoX_mAW43o2zCA&usg=AFQjCNEXI3RGmd2AyCVAl2znGF_BRbo_yw (Accessed 10.03.12)
[3] Monash IVF,(2011). History of IVF (Online) Available: http://www.monashivf.com/About_Monash_IVF/History_of_IVF.aspx (accessed 10.03.12)
[4] Monash IVF. 2012. PGD and Gender. (Online) Available: monashivf.com%2FInformationLibrary%2FDoes_monash_ivf_offer_pgd_for_sex_selection_.aspx&ei=ESRkT_LYPKWYmQWHl8iECA&usg=AFQjCNEoJJv_rLWGsbPp0cOn1o82lULiEw ( Accessed 10.03.12)
[5] Dixon,P. Global Change.com. 2011. Gender Selection: is it right? (online) Available:      ://www.globalchange.com/select.htm ( Accessed 10.03.12)
 [6] Weyers, Kate. Journal article 2010.  Prenatal Torts and Pre-Implantation Genetic Diagnosis
; Harvard Journal of Law & Technology, Vol. 24, 2010 (online) Available:
 http://www.questia.com/PM.qst?a=o&d=5049575109 ( Accessed 10.03.12)



1 comment:

  1. Preimplantation Genetic Screening (PGS) with Parental Support offers a new technology that gives couples the best chance of having healthy babies.

    PGD Preimplantation Genetic Diagnosis

    ReplyDelete