2015 Group Project 6
| 2015 Student Projects | ||||
|---|---|---|---|---|
| 2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students | ||||
| 2015 Group Project Topic - Assisted Reproductive Technology | ||||
| This page is an undergraduate science embryology student and may contain inaccuracies in either description or acknowledgements. | ||||
Prenatal Genetic Diagnosis for ART
Introduction
History
Indications
Inheritance patterns
Preimplantation Genetic Diagnosis
Preimplantation genetic diagnosis (PGD) is used to test the genetic makeup of embryos to prevent the transmission of inherited diseases with detrimental effects such as cystic fibrosis, spinal muscular atrophy and beta – thalassaemia [1] [2]. It was first used in the United Kingdom in the 1980s of arenoleucodystrophy and primarily focusing on sex- linked disorders [3] [4]. PGD is now capable of detecting single cell defects (molecular) and chromosomal disorders resulting from the inversion, translocation or deletion of chromosomes (cytogenic) [5] [6].
PGD can be applied to different the embryo at different stages. That is on polar bodies, blastomeres or blastocyst [7].
- Polar bodies: Applying PGD to polar bodies is desired as it can be used before conception. Since genetic testing can be conducted within twenty four hours this makes it possible for the transfer to the mother at the blastomere stage. However this method isn’t commonly used due to the fact that all oocytes must be tested including those that may not progress to mature and only genetic material from the female can be retrieved [8].
- Cleavage stage: This involves the biopsy of the blastomere (6 to 10 cells)[9]. It is advantageous to work on blastomeres as they are totipotent, meaning they can give rise to a diverse range of cells. Studies have also shown that there is no increase in congenital abnormality rates caused by the removal of blastomere cells [10]. Contrarily, studies have shown that the standard removal of two blastomeres at one time will decrease its potential to develop into a blastocyst [11]. Along with the fragility of the cells at this stage, highly skilled embryologists are required to minimise poorly performed biopsies which could subsequently lead to impaired growth and a decrease in implantation. Unlike polar bodies both maternal and paternal genes can be tested if PGD is performed at this stage [12].
- Blastocyst: Performing PGD at this stage is the least common since many patients do not produce embryos healthy enough to reach this stage. Multiple cells can be extracted at this stage for biopsy producing more accurate results. This is possible due to the fact that biopsies have little effect on the development of the embryo. Genetic tests must also be conducted rapidly since implantation is optimal at this stage [13].
Depending on the type of genetic disorder, PGD utilises different methods of genetic testing. These include Fluorescence in situ hybridisation (FISH) which is used for sex – linked disorders and detects chromosomal rearrangements [14] [15] and Embryo halotyping which allows the identification of chromosomes causing the inherited disorder through knowledge of the pattern of closely linked markers [16]. Polymerase chain reaction (PCR) is also widely used to detect molecular abnormalities [17].
Preimplantation Genetic Screening
Cell Extraction Methods
Polar Body Analysis
Blastomere biopsy
Trophectoderm biopsy
Genetic Techniques
Fluorescent In Situ Hybridisation (FISH)
PCR
Diagnosis
Utilization of Diseased Cell Lines
Laws & Legal status
Future/Current Research
Ethics
References
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>17823145</pubmed>
- ↑ <pubmed>17823145</pubmed>
- ↑ <pubmed>23150080 </pubmed>
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>11325751</pubmed>
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>11325751</pubmed>
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>19773223</pubmed>
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>11325751</pubmed>
- ↑ <pubmed>17876073</pubmed>
- ↑ Coward, K. & Wells, D. (2013).Textbook of Clinical Embryology New York: Cambridge University Press
- ↑ <pubmed>11325751</pubmed>
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- 2015 Course: Week 2 Lecture 1 Lecture 2 Lab 1 | Week 3 Lecture 3 Lecture 4 Lab 2 | Week 4 Lecture 5 Lecture 6 Lab 3 | Week 5 Lecture 7 Lecture 8 Lab 4 | Week 6 Lecture 9 Lecture 10 Lab 5 | Week 7 Lecture 11 Lecture 12 Lab 6 | Week 8 Lecture 13 Lecture 14 Lab 7 | Week 9 Lecture 15 Lecture 16 Lab 8 | Week 10 Lecture 17 Lecture 18 Lab 9 | Week 11 Lecture 19 Lecture 20 Lab 10 | Week 12 Lecture 21 Lecture 22 Lab 11 | Week 13 Lecture 23 Lecture 24 Lab 12 | 2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students | Student Designed Quiz Questions | Moodle page
