Down Syndrome (Trisomy 21 and Translocation)

[Kirstyloo]

During egg development, meiosis is blocked at prophase I until ovulation. Most instances of nondisjunction maternal occur during prophase I not during meiosis II as noted in the video. Meiosis II occurs following fertilization. Therefore, it occurs right before conception not during embryogenesis.

The second issue is picture of the translocation. Non-classical Down syndrome is associated with a Robertsonian translocation not a reciprocal translocation as illustrated in the figure. Chromosome 14 and 21 are acrocentric chromosomes meaning that they have very tiny short arms. The short arms are both lost in a reciprocal translocation and both long arms are connected by the “new” centromere.

While these changes are unlikely to impact most people’s understanding of the topics, they could cause problems for some going into selected medical professions.

Thank you!

[MyProudbelieber]

I learned more with your video than with my teacher! And english is not even my native language. Thank you so much!

[Beinghumane]

Seriously, this is the video I needed, very in-depth clarity . Thanks for this❤

[fqkgcep]

Thank you. I can’t skip one of your video without putting like at the end. As always Informative and to the point 👍🏼👍🏼

[dominicgrey]

I really loved this video! I too post videos in support of our Down Syndrome toddler only to spread awareness, cause when we discovered we were blessed with a trisomy21 child we were clueless on expectations and who or where to turn to for guidance and support. I subscribed to your channel to demonstrate support. Great Video!

[monicaengleson]

Amazing, Thank you. I don't know how you do it but it just clicks when you explain it.

[chooblalldharamdin]

I learn something more today, which I was barely known about yesterday. thank you.

[xoxrandomgirlxoxlol]

there is also mosaicism :D But- OMG! You're such a life saver! I have spent hours trying to wrap my head around translocation. Awesome video- subscribed! :D <3

[kamanbossip]

have been reading the whole time trying to understand the concept but didn't really, but thank you for this video. I really understood the concept.

[CurtiousOne]

Thank you very much for this video. I've been trying to clearly understand this concept for a couple of days now, and you tied it together very well!

[hudhaimaissa]

Thnks sir presentation esp on translocation

[dillonbyerley]

Thank you for your explanations. You explained this concept very well!

[michaelseifert]

You're a freaking teacher superhero!

[alcondragon]

As I begin to do research on down syndrome, and as I do understand that down syndrome is caused by a random error in cell division that results in the presence of an extra copy of chromosome 21, I am driven to a possible solution that this can be averted or overturned by a change in the acid or alkaline levels during the growth in the womb. Each of the 23 chromosome must have a slight difference in chemical structure by analysis, and by associated stages of growth, should be able to be treated as to configure and maintain normal health values in all the variations. If the blood test does not exist then one must be created by which the fetus can be tested and treated. This would be crucial to diagnose and treat many of the prebirth diseases. Thank You!

[isaialvarado]

You are great, I'm from Mexico, I don't speak very well English, but I really understand this video, I thanks

[soul]

Thank you . But i do not understand why the number of eggs is four ? I thought that the resulting of miosis one is two cells, one of them (first polar body) does not divide and another can divide to give two cells too, one of them (second polar body) and the another is the ovum, so the result is just one cell ( the ovum ), right ?

[hawraa]

since yesterday, I was looking for this, finally, I get what exactly the translocation between chromosome 21 and 14 is, thank a lot

[guadalope]

you are genius, , thank you indeed... simple and confident presentation.

[saunyboy]

Just one correction - at metaphase II the chromatids are no longer sister chromatids due to prophase I crossing over, other than that great explanation

[tlalti]

Thank you for a very simple to understand explanation.