Talk:2015 Group Project 6
2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students
Links to Project Discussion Pages: Discussion 1 | Discussion 2 | Discussion 3 | Discussion 4 | Discussion 5 | Discussion 6
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Abnormal Development - Genetic FISH Image [1] associated copyright [2] fish data - [3] [4] [5]
--Mark Hill (talk) 11:26, 25 September 2015 (AEST) OK this is such an easy project to find resources for, so where are they? Everyone in research, support groups, genetic inheritance are talking about this topic and the techniques. But this is not on your project page.
Like my comments for the other project pages, animal models and media, graphics, statistics, graphs to support the project information???? Your project is not ready for peer review.
--Mark Hill (talk) 16:26, 1 September 2015 (AEST) I would like to see some content (sub-headings) on your project page.
Peer Reviews
1
I’ll start by saying, you have an extremely extensive list of references. Well done! It shows you have really done your research and made good use of it. Your citations are consistent throughout the page and most paragraphs have multiple sources. I would suggest to perhaps include a hand-drawn image somewhere on the page as well as a video. Aside from the section “biopsy methods”, the page could use a few more illustrations. From what I can see, the image under the subheadings “FISH” and “future/current research”, does not appear to have been added correctly according to the guidelines Mark gave us a few weeks back. There is no caption for the image like there are for the other images.
I really like, how under the “diagnosis” heading, you have made the table of applicable diseases for PGD an expandable table. It helps keep the page clean and easier to control. Perhaps though add a little blurb below the table describing it. You have a great set of heading and subheadings that all relate back to your topic. Given that, you have addressed all important areas pertaining to your topic. May I suggest, that in the introduction section, which I am assuming is yet to be done, you add some epidemiological information and perhaps a video speaking briefly on the topic as it can be quite complex.
Well done on the section titled “future/current research”. It is really useful for students seeking a higher degree of information on this topic as it goes into great detail. However, some direct references in the text to some papers would be good. I also suggest adding a glossary of words to the bottom of the page to cater to those who read the page, with a lower level of embryology knowledge than you or I. In addition to that, it may be good to try and break-down some of your paragraphs as there is a lot of text and it can be hard to take in for some people. Bullet points and tables are great. The page does however, focus well on embryological learning aims.
Lastly, to conclude, I feel a though the table and image under “biopsy method” is a little cluttered and could be spaced out a bit more. Overall, this is a really good and detailed framework and with a little more work will be a great project.
2
A very snazzy wiki page so far! You have used a wide variety of images to convey the concepts of prenatal genetic diagnosis to those reading your wiki page. Copyright information and student templates were present for all the images which you provided which is great to see. A hand drawn image is absent, which is a requirement for every wiki page. It might be worth including the hand drawn image in the 'history section' as the information here could easily be represented by a hand drawn flow chart.
I commend you on your inclusion of a 'future/current research' subheading as this gives the reader a perspective of where the field of prenatal genetic diagnosis is heading in the distant future.
I see that you have included a table underneath the 'biopsy methods' subheading. It would be great to see you compile the advantages and disadvantages of blastomere biopsy and trophectoderm biopsy into a tabular format as this would make for an easier reading experience. Furthermore, tables may also be incorporated for the disadvantages and advantages of genetic techniques. I would recommend the inclusion of other forms of media such as a video or gif to assist in the conveyance of information under certain subheadings. A video/gif would fit nicely underneath the 'biopsy method' subheading, though this is just a suggestion.
Overall your assignment is superb so far. You have successfully covered a vast topic and made successful use of a broad range of sources to support your page. Your inclusion of images has been appropriate, however a hand drawn image is still required. Keep up the good work guys!
3
COMMENDATIONS
• Good reference list and in text citations throughout.
• Great table of advantages and disadvantages under “Biopsy Methods” (good comparison of the techniques). However, the ‘Blastomere’ row is missing information.
• All key points have been addressed, and it is evident that you have done a lot of research!
RECOMMENDATIONS
• A short definition at the beginning of your page would help the reader understand what your topic is about. I was a bit unsure as to what ART was when I first began reading.
• Your information could be organised under more subheadings, particularly in your “Polar Body Analysis” section; the information here is quite dense.
• More pictures or animations would be great; make sure you reference your pictures properly as well (the image under FISH is missing a reference).
• More tables – a lot of your information involves advantages and disadvantages. You could create more tables to make the information easier to read/follow. It would also allow you to cut down on details that are repeated, or those that you do not need.
• A self drawn diagram is also missing – maybe this could take the form of a world map and you could label the various countries featured under your “Laws & Legal Status” heading with their respective laws.
It is evident that you have put in a lot of effort into your page. Try and condense the information you have, and add more titles and images to create a more succinct end product. Good job so far!
4
This page contains a lot of interesting information regarding the chosen topic, and has been accompanied by some really useful images. I was particularly intrigued by the information you have provided for genetic techniques and hope to see some more images and videos to help your explanation. Especially for PCR, this is a widely used technique for genetic analysis and I am sure there are some really good videos on YouTube you can add to this section. For these procedures, you have also listed a great amount of disadvantages and advantages but it would be easier to read if this were in a table format.
I believe the headings are extremely relevant and cover the correct areas of focus for this topic. However, the use of sub-headings is lacking which makes it difficult for the reader to initially understand the areas that will be discussed on this page. You can easily change the bolded headings under “Indications”, “Preimplantation Genetic Screening”, and “Biopsy Methods” into subheadings with a minor edit. On that note, the table presented in the “Biopsy Methods” is quite confusing as the advantages and disadvantages of “Blastomere” are absent. Also, further elaboration on these headings is needed for the reader to gain an adequate understanding of the topic.
You have provided a really good framework to add more content on this page. This is especially required in your heading of “Diagnosis”. I think a more detailed explanation about how the diseases are linked to PGD is needed to avoid confusion. When I first read it, it didn’t make much sense so perhaps use an image of how these diseases relate to PGD could mend this.
The addition of a “Future/Current Research” heading is very well done. This demonstrates you have thought beyond the mechanics of describing PGD and are looking into extra sources. You may want to consider separating future research from current research to make the page more systematic, and to clearly show what scientists are looking to achieve later. The image in this section is also really good as it is clear and shows the process of extraction. More images, videos or GIFS may be needed to effectively convey the research and procedures to your audience.
Lastly, your reference list is extremely impressive. You have shown you have conducted numerous and successful literature searches and are utilizing them accordingly. An important thing to note is that you are lacking in-text references in a few sections, especially “Biopsy Methods”, and in your lists of advantages and disadvantages. Make sure to add these to avoid academic misconduct to allow your reader to do further reading if they wish.
Overall, this is a really good page so far. You have demonstrated great teamwork and strong efforts to make this page standout. I suggest you consistently edit your work, add more visual aids, and condense your information where possible to gain the mark you deserve. Fantastic work!
5
There is no introduction, not having an introduction would mean there is no overview of what this page would be about and what it will discuss in detail. If an introduction could be uploaded maybe consider an image or a short video that would be able to sum the introduction up. This must be done instead of just going straight into the “History “.It would make your page more appealing and professional if you followed through with an introduction. Other than that, I appreciate the detail that went through. There is great amount of reference at the end of each section which is great, however there is no in- text referencing in some sections like procedure of “Genetic Techniques”. Having in-text referencing will allow the audience to know exactly where the information was read from and for the interest of the audience can read that specific paper in detail. There is a great amount of information in almost every section with great detail however, consider more subheadings to make the sections easier to read and allows the audience to navigate the page effortlessly. This was the case for ““Polar Body Analysis” section”. The information here is quite dense therefore you could split or organize information into more subheadings.
I also noticed that there is not enough information in historic findings; this is an important key point that needs to be addressed. Present some online research, add some images, some in text referencing and maybe a table or timeline, this should help shape the historic findings section. Finding information on historic findings might be a little challenging. A suggestion I can make is to search for old articles in PubMed (by adjusting the year). Review articles that summarise historic findings related to Prenatal Genetic Diagnosis may also be helpful. You also need to find information on current research as well. Other subheadings that are either incomplete or missing are “Ethics “and “Future/Current Research”. This can to be done in the same manner as the historic findings. The tables displayed in the other sections are great as they simplify information and is an effective way for students to study so well done! Keep in mind this is meant to be informative and easy to comprehend, so try and find that balance. Thus, consider some more images, diagrams, graphs and tables in each section, to make it more inviting and not overwhelming with just content. Captions should be added on the page for some of the images to state what the images are showing.
Try and look for a youtube video that can help summaries the content on your page. If possible try adding hand drawn images too. A glossary list should be incorporated in a separate subheading to define some of the technical words so that viewers can fully grasp the information.
Having said all those down side points, this page is coming along nicely with many positive aspects:
• Great amount of references at the end
• Concise in text citation except in some paragraphs
• Good use of images
• The use of dot points in different sections to format the info is very useful and provides clarity
• Great table of advantages and disadvantage in section “Biopsy Methods”
• The key points have been clearly described
• Having Future/Current Research” sub heading which is great
Overall, I can appreciate the difficulty of this topic. However if you work on the subheading within each section and add some images, videos and diagrams as well as some in text referencing I think that should make a significant difference by making this page more inviting, easier to navigate and also appear greatly organized. GOOD LUCK
6
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Discussion
Z5088434(talk Would the part you added in indication rather be part of the introduction since it pretty much sums up what the page is about? Maybe go into when PGD and PGS are applied? as for the multiple instances citations: first in text citation has to be like this: [1] and the following ones are like this: [1] (just check for the code in the edit mode, can't figure out how to just show the code without it actually configuring it...)
To Do List
Week 4
- text book summary and some notes
- journal article
- 1 relevant media article
- post in this discussion and on your own page under lab 3 assignment
- for links or informal questions please use the facebook Group
Prenatal Genetic Diagnosis
Headings
- Polar body
- Genetic techniques
- Laws in different countries and states
- Cell extraction from zygotes, blastomeres, morula
- How analysis is conducted e.g. PCR
- Gene Mapping
- Inheritance patterns
- Conducted prior to implantation
In order (?):
- Introduction (GP)
- History/Development (include transition from post to preimplantation) (GP)
- Indications, Inheritance patterns (SL)
- Preimplantation Genetic Diagnosis (PGD)
- Preimplantation Genetic Screening (PGS)
- Cell Extraction Methods, side effect (SK)
- Polar Body Analysis
- Blastomere biopsy
- Trophectoderm biopsy
- Genetic Techniques (GP)
- Fluorescent In Situ Hybridisation (FISH)
- PCR
- Array Comparative Genomic Hybridisation (aCGH)
PMID 26100406 PMID 24771116
- Single Nucleotide Polymorphism
history explanation specific examples application
Next Generation Sequencing
- Diagnosis (table, gene mapping) (SL)
- Utilization of Diseased Cell Lines (SK)
- Laws/ Legal status (SL)
- Future/Current Research
- Ethics
Content
Legistation for ARTS
Assisted Reproductive Technology Ethics
G12 Country Regulations of Assisted Reproductive Technologies
Cell Extraction Methods
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 [2]
Cleavage stage: This involves the biopsy of the blastomere (6 to 10 cells) [3]. 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 [2]. Contrarily, studies have shown that the standard removal of two blastomeres at one time will decrease its potential to develop into a blastocyst [4]. 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. [2]
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 [2]
Textbooks
The Developing Human 9th Edition: Birth Defects caused by Genetic factors
- Estimated to cause one third of all defects
- Abnormalities in chromosomes are usually due to structural or numerical changes. These can occur in sex chromosomes or autosomes.
- Numerical abnormalities are a result of nondisjunction. Nondisjunction is when a pair or chromatids fail to disjoin during meiosis or mitosis. E.g. Turners Syndrome, Trisomy 21 (Down syndrome) and Trisomy 18 (Edward’s Syndrome).
- Structural abnormalities are usually a result of chromosome breakage followed by reconstitution in an abnormal combination. There are different types of structural abnormalities including translocation and deletion of chromosomes
- Mutations cause 8% of birth defects. It involves the loss or change in the function of a gene which is permanent and heritable.
Williams Obstetrics, Twenty-Fourth Edition: Preimplantation Genetic Testing
- two categories of preimplantation genetic testing: PGS (-Screening) & PGD (-Diagnosis); different indications
- PGS: IVF procedure due to infertility without known genetic abnormalities in patients
- PGD: IVF procedure & genetic testing chosen because of known genetic abnormalities in patients
- Methods:
- Polar body analysis: first and second polar body are extruded following completion of meiosis I and meiosis II
- Advantages: does not harm embryo, can be used to detect 146 Mendelian disorders, reported 99% accuracy
- Disadvantages: paternal genetic contribution is not investigated --> additional procedures
- Blastomere biopsy: embryo is 3 day old, 6-8 cells stage, most commonly used, hole is made in zona pellucida to retrieve one cell
- Disadvantages: 10% pregnancy reduction,"mosaicism of the blastomeres may not reflect the chromosomal complement of the developing embryo"
- Trophectoderm biopsy: 5-6 day old blastocyst, 5-7 cells are removed
- Advantage: no cells removed from embryo
- Disadvantage: additional procedures may be necessary because of later stage of developing embryo (cryopreservation, implantation at later IVF-cycle)
- Polar body analysis: first and second polar body are extruded following completion of meiosis I and meiosis II
Maternal, Fetal & Neonatal physiology: a Clinical perspective :Prenatal Diagnosis and Maternal, Fetal & Neonatal physiology: a Clinical perspective: Prenatal Diagnosis:
Prenatal diagnosis is the screening process that tests an early fetus for overall growth, complications of pregnancy, birth defects and chromosomal or genetic abnormalities within the first 2 trimesters. It aims to provide the parents with as information as possible to help them make an informed decision about the infants quality of life. In 90-95% of the cases negative outcomes occur; confirming the healthy state of the fetus, should a genetic abnormality be present, it provides the parents with the opportunity to investigate further with other tests, and possible fetal therapeutic treatments available as well plan and prepare for the disabled infant or to terminate the pregnancy.
- Indicators for prenatal screening/ high risk factors include:
- maternal ages > 35 years
- paternal ages > 50-55
- history of 2+ miscarriages
- previous pregnancy or family history of a preexisting genetic or chromosomal disorder
- suspected carriers of genetic disorders
- maternal disease/condition present (high BP, diabetes)
- abnormal ultrasound or serum test results within the first 2 trimesters
- family history of neural tube or other birth defects
- Ultrasonography:
- high frequency sound waves are used to generate a image of the fetus
- relatively non-invasion; its conducted transabdominally or transvaginally ( producing a higher resolution image)
- It reveals the presence/absence of congenital abnormalities, characteristics of fetal growth and development, uterine development status; amount of **amniotic fluid, placental position, umbilical blood flow and the presence of multiple gestation.
- (if abnormalities are detected further testing is recommended)
- Amniotic Fluid Analysis/:
- samples are obtained through amniocentesis
- the amniotic fluid is analyzed for its biochemical composition
- earlier in the pregnancy it can be examined for sex determination and to diagnose genetic or chromosomal disorders present.
- Later into the pregnancy it provides an indication of fetal maturity and well being
- Feta; cells recovered from the amniotic fluid can be cultured for specific karyotypes, to test for Chromosomal Abnormalities, and analysed for Alpha- fetoprotein (AFP) a biochemical marker of metabolic disorders and neural tube defects as well as other abnormalities.
- Amniocentesis- occurs usually between weeks 14-20 as amniotic fluid has reached the optimal volume (150-250mls) allowing 20-30mls to be removed with a relatively low risk or fetal or maternal complication, and in time for a 2nd trimester abortion.
- early amniocentesis ( before week 13) increase the risk of fetal loss, leakage of essential amniotic fluid and talipes equinovarus.
- Chronic Villus Sampling (CVS):
- occurs roughly 10-13 weeks after last menstrual cycle, ensuing a sufficiently developed chorionic villi but before the chorion laeve forms the definitive placenta.
- ultrasounds is used to locate the gestational sac and implantation then a transcervial or transabdominal approach is used to aspirate living tropoblast tissue.
- sample is analyzed for chromosomal abnormalities or with enzyme assay.
- advantages: earlier diagnosis , decreased waiting period
- disadvantages: risk of spontaneous abortion, bacterial infection, bleeding, leakage of amniotic fluid, inability to diagnose neural tube defects this early, early cleavage (before wk 10) is associated with increased risk of limb defects (due to insufficiently developed chronic villi)
- Umbilical Blood Sampling:
- can occur as early as 16 weeks
- using the umbilical cord to obtain fetal blood samples - with real time ultrasound
- used to diagnose inherited blood disorders, to detect congenital infections, to assess fetal anemia and in treatments such as blood transfusions.
- disadvantages: risks of infection, preterm labor, thrombosis, bleeding & transient fetal arrhythmia
- Fluroscent in Situ Hybridisation (FISH)
- rapidly detects (within 24 hours of testing ) the presence of Trisomies 21, 13 and 8 and alterations in sex chromosomes in uncultured cells.
- early diagnosis allows the opportunity for intervention with fetal therapies:
- surgical intervention urinary tract obstruction ; aiming to reduce prenatal renal damage
- fetal transfusions ( feta anemia
- fetal medical treatmetn ( fetal cardiac arrhythmias,impaired thyroid function etc.) treatment occurs usually through the mother
- infusions for hematologic conditions
- stem cell transplantation
- gene therapy
- pharmocolic interventions
textbooks used :
- Maternal, Fetal & Neonatal physiology: a Clinical perspective [7]
- Langman's Medical Embryology (12th ed.)Chapter 9, pages 125-129 [8]
the following are two articles about a newly available and accessible prenatal non- invasive genetic test- Blood sampling:
- Report on Cutting edge prenatal screening technology to become available in Australia [9]
- Blood Test takes risk out of prenatal testing [10]
- Prenatal screening and Diagnostic Tests Information Pamphlet [11]
Articles
<pubmed>24810687</pubmed>
<pubmed>23773313</pubmed>
<pubmed>26201722</pubmed>
<pubmed>26168107</pubmed> This article reviews the cytogenetic techniques and embryo biopsies required for PGD & PGS and gives an account on the differences in PGD for single gene defects and chromosomal translocations.
<pubmed>22723007</pubmed>
This article gives relatively recent and detailed information on the three types of biopsy performed on embryos at different stages of development (before conception, after fertilization, and early cleavage or blastocyst stage)
<pubmed>24515905</pubmed>
This article reviews indications for PGD focusing on single gene disorders.
<pubmed>20966459</pubmed>
This article gives detailed laboratory instructions and guidelines for PGD procedures, which might be useful for the methodological part of the website
The following articles are about diseased cells/embryos derived from PGD procedures for further research:
<pubmed>23242925</pubmed>
<pubmed>22735930</pubmed>
Other articles
<pubmed>21748341</pubmed>
<pubmed>26259216</pubmed>
<pubmed>26258137</pubmed>
<pubmed>22404048</pubmed>
<pubmed>26238130</pubmed>
<pubmed>26168107</pubmed>
IVF and prenatal genetic testing in Australia
[[6]]
the following are two articles about a newly available and accessible prenatal non- invasive genetic test- Blood sampling: [[7]] [[8]]
- ↑ 1.0 1.1 <pubmed>...</pubmed>
- ↑ 2.0 2.1 2.2 2.3 Coward, K. & Wells, D. (2013). Textbook of Clinical Embryology New York: Cambridge University Press.
- ↑ <pubmed>11325751</pubmed>
- ↑ <pubmed>19773223</pubmed>
- ↑ Moore, K.L., Persaud, T.V.N. & Torchia, M.G. (2011). The developing human: clinically oriented embryology (9th ed.). Philadelphia: Saunders.
- ↑ Cunningham F, Leveno K.J., Bloom S.L., Spong C.Y., Dashe J.S., Hoffman B.L., Casey B.M., Sheffield J.S. (2013). Prenatal Diagnosis. In Cunningham F, Leveno K.J., Bloom S.L., Spong C.Y., Dashe J.S., Hoffman B.L., Casey B.M., Sheffield J.S. (Eds), Williams Obstetrics, Twenty-Fourth Edition. Retrieved August 25, 2015 from {http://accessmedicine.mhmedical.com/content.aspx?bookid=1057&Sectionid=59789152.}
- ↑ Blackburn, S.L. (2003) Maternal, Fetal & Neonatal physiology: a Clinical perspective (2nd ed.). Seattle: Saudners
- ↑ Sadler T.W.(2012) Langman's Medical Embryology (12th ed.) Philadelphia: Lipincott, Wiliams & Wilkins, a Wolters Kluwer Business
- ↑ Carbonell, R. Shinners, A. Amor, D. Mark, D. (2015) Report on Cutting edge prenatal screening technology to become available in Australia: Prepared for ABC news, PM with Mark Colvin. Retrieved from {http://www.abc.net.au/pm/content/2015/s4203200.htm}
- ↑ Begley, S. (05/07/2015) Blood Test takes risk out of prenatal testing. ABC Science. Retrieved from {http://www.abc.net.au/science/articles/2012/07/05/3539549.htm}
- ↑ Western Australia. Department of Health Genetics Council Prenatal Diagnosis Committee (2011)Prenatal screening and Diagnostic Tests. Retrieved from {http://www.health.wa.gov.au/docreg/Education/Prevention/Genetics/HP3131_prenatal.pdf}
![[1]](https://www.genome.gov/images/content/FISH_factsheet.jpg){kind=link}