Marfan Syndrome, Osteogenesis Imperfecta & Ehlers Danlos, Blue Sclera Hypermobile Joints Stretchy

www.stomponstep1.com/marfan-sy...
Collagen is the key component of connective tissue. Triple helix of individual procollagen chains (composed mainly of Proline and Glycine) are created in the fibroblast. Outside of the fibroblast collagen undergoes extensive posttranslational modification such as crosslinking via Hydroxyl-Lysine. Vitamin C is an essential cofactor for the hydroxylation of lysine and deficiencies (Called scurvy) lead to weak collagen.
Type I collagen = bones & scar. Abnormal in Osteogenesis Imperfecta
Type II Collagen = Cartilage.
Type III Collagen = Skin, vessels & granulation tissue.
Type IV Collagen = Basement membrane. Abnormal in Alport Syndrome
Fibrillin/Elastin = Ligaments & Lungs. Abnormal in Marfan Syndrome & Emphysema
Just think that type 1 is the strongest and it gets progressively weaker with each higher number. Bone (1) supports the whole body, cartilage (2) supports small parts of the body, skin (3) is a relatively weak covering, and basement membrane (4) only supports a layer of individual cells.
Osteogenesis Imperfecta is a genetic disease that causes a defect in type 1 collagen. It results in many fractures, Blue Sclera, and hearing loss.
Ehlers-Danlos is a disease caused by abnormal collagen synthesis. Different types of Ehlers-Danlos effect different types of collagen. The most common presentation includes "stretchy" skin, easy bruising, aneurysms (due to weak vessels) & hypermobile joints.
Marfan Syndrome is a disease caused by abnormal Fibrillin (component of elastin) formation. Classically presents as a Tall patient with hypermobile joints. Mitral valve abnormalities and Aortic Dissection are also frequently seen.
Now that you are done with this video you should check out the next video in the Biochemistry section which covers Tay Sachs Disease, Gaucher & Neiman Pick (www.stomponstep1.com/tay-sachs...)
Pictures Used:
• This work is a derivative of "Characteristically blue sclerae of patient with osteogenesis imperfecta" by Herbert L. Fred, MD and Hendrik A. van Dijk available at commons.wikimedia.org/wiki/Fil... under Attribution-Share Alike Creative Commons 3.0
• This work is a derivative of "Ehlers Danlos Syndrome" by Piotr Dołżonek available at en.wikipedia.org/wiki/File:Ehl... under Attribution-Share Alike Creative Commons 3.0
• This work is a derivative of "Ehlers Danlos Thumb" by Piotr Dołżonek available at en.wikipedia.org/wiki/File:Ehl... under Attribution-Share Alike Creative Commons 3.0

[@Squeek1227]

Great video. One thing I noticed is that you said Collagen Type III is a component of skin. Thats fair to say, although Type I is much more prominent (>2:1 ratio) in adults (fetuses 1=3). (Source: www.academicjournals.org/article/article1380878500_Cheng%20et%20al.pdf in table 1 shows ratios) Also a great mnemonic for all of those trying to memorize these collagens that I use (stole) is: 1. bONE 2. CarTWOlage 3. ReTEEculin (THREE; obviously not spelled right but helps me remember) 4. Basement membrane FLOOR (FOUR) Great review on key findings though! Thanks!

[@adrenalinejunkie888]

These videos are helping me out so much! thank you!

[@stomponstep1989]

If you liked this video and want me to make more please let me know by commenting, liking this video or by subscribing to my KZbin channel. If you have a question, please don’t hesitate to ask and I’ll try to answer it ASAP.

[@victoriateague9966]

thank you!!!

[@jeffr3773]

Thanks.

[@eJODIann]

awesome videos while reviewing for step 1! thanks!!

[@stomponstep1989]

Jodi-Ann Edwards Thanks! Please tell you friends

[@ArielCarso]

The videos are great. I would just ask that you increase the volume of the audio. Thanks bunches!

[@pippasmith7818]

I have osteogenesis thingy

[@pippasmith7818]

Omg I have both of those proved by dna tests

[@afrotravis]

u subscribed... but please dont stop making the videos....

[@zho0616]

this is great but those first 40 secs are annoying lol THank you!