Chediak-Higashi Syndrome, I-Cell Disease, Kartageners Microtubules Inclusion Cell Disease

www.stomponstep1.com/chediak-h...
The cytoskeleton is a network of scaffolding that gives cells their shape. The cytoskeleton is made up of intermediate filaments, microtubules, actin, and myosin. Microtubules are cylinders of tubulin that can dynamically assemble and disassemble to change length. Microtubules are very important for multiple types of cellular movement (Mitosis, Axonal Trafficking, Cilia/Flagella...). Motor proteins Dynein and Kinesin travel along microtubules like trains on a track causing these movements. Microtubule functioning is inhibited by drugs like Colchicine (gout), Vincristine (cancer), Paclitaxel (cancer) and Mebendazole (parasites).
Kartagener's Syndrome (Primary Ciliary Dyskinesia) is a genetic defect in Dynein motor proteins that prevents proper functioning of the Cilia. Cilia normally beat in a rhythmic wave forcing foreign material out of the body. Immotile cilia in the sinuses, ear, and respiratory tract result in Recurrent Infections (sinusitis, otitis media, pneumonia & bronchitis). Abnormal cilia also lead to Infertility in men (immotile sperm) and women (vaginal mucus builds up and is too thick).
Chediak Higashi is a genetic defect in phagocyte microtubules which fuse the phagosome and lysosome. The defect prevents phagocytes from destroying what they engulf and Giant Granules of undigested material builds up. This causes Recurrent Infection (impaired phagocyte function), Albinism (impaired melanin trafficking) & peripheral neuropathy (impaired axonal transport).
I-Cell Disease (Inclusion-Cell Disease) is a genetic defect which limits the ability to phosphorylate mannose in the golgi and leads to abnormal cellular trafficking. Mannose-6-Phosphate usually signals newly made enzymes to be delivered to the lysosome. Without this signal these enzymes meant for the lysosome follow the "default" trafficking pathway and are secreted outside of the cell (into the extracellular matrix) damaging other cells. Patients present with lysosomal enzyme deficiencies and the presence of Lysosomal Enzymes Where They Shouldn't Be (Blood, Urine...). This leads to a wide variety of symptoms such as Abnormal Facial Features, joint problems, and short stature. Additionally, lysosomes cannot function properly in degrading cellular debris which causes accumulation of cellular debris in the lysosome and the formations of inclusions bodies.
Now that you are done with this video you should check out the next video in the Biochem section which coversMarfan Syndrome, Osteogensis Imperfecta & Ehlers Danlos (www.stomponstep1.com/marfan-sy...)
Pictures Used (In order of Apearance)
• This work is a derivative of "Microtubules and Alkaloids" by Simon Caulton available at commons.wikimedia.org/wiki/Fil... under Attribution-Share Alike Creative Commons 3.0
• This work is a derivative of "Spindle Aparatus" by Lordjuppiter available at en.wikipedia.org/wiki/File:Spi... under Attribution-Share Alike Creative Commons 3.0
• This work is a derivative of "Kartagner" by Filip Em available at en.wikipedia.org/wiki/File:Kar... under Attribution-Share Alike Creative Commons 2.5
• This work is a derivative of "Alpha-Mannosidosis Electron Micrograph" by Dag Malm and Øivind Nilssen available at en.wikipedia.org/wiki/File:Alp... under Attribution Creative Commons Generic 2.0

[@stomponstep1989]

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[@wingchunjourney]

Been watching your video to refresh concept for Step 1. Super helpful. Thanks!

[@madelinebell9158]

Great video! I would appreciate (if you ever have the time) a link to other videos explaining the "no-yield" topics. They aren't super important for Step but M1 professors love to test us on them regardless.

[@jeffr3773]

You're the greatest, keep going.

[@ranataher2566]

More than brilliant . Keep it up and upload more 👍.

[@boletinclinicodentalsynerg7382]

Excellent material! keep up the good work

[@marypennington3899]

love your videos man, soothing, calm voice, attitude chilled, good chit mon~~~

[@africa9193]

really good and precise.thanks

[@olubunmiogunmola1028]

nice job ,very precise and pls more videos

[@hannahmiller8890]

These are great! thanks!

[@stomponstep1989]

Hannah Miller Thanks for the comment!

[@paolaarevalo9086]

Very nice videos! very helpfull ! thank you

[@stomponstep1989]

+Paola Arevalo thanks for watching!

[@aslemercito]

it is of great help I found very easy to understand!!!

[@stomponstep1989]

+aslemercito Thanks for commenting!

[@rayanhabib9535]

Your videos are very helpful ,please keep posting :-)

[@stomponstep1989]

Rose Zara Thanks! I'm studying for Step 2 right now, but I plan to start making more videos after I get done with Step 2. My 4th year schedule should give me a lot more time to work on the project

[@rayanhabib9535]

Thank you for your response and good luck with your step 2!

[@manushoganyan6302]

Thank you :)

[@stomponstep1989]

+Manush Oganyan thanks for watching!

[@ameneh212]

Thanks for the video. It helps me alot when the explanation is simple and clear. Could you make one regarding cilia disfunction on diabetes. Thanks a lot

[@stomponstep1989]

Amy G Thanks for the feedback! Are you studying for the USMLE Step 1 or something else? Cilia problems in diabetic patients is very low yield for step 1 so I probably wont end up covering that topic

[@mohammadzagzoog859]

big thanks...

[@stomponstep1989]

Mohammed Zagzoog thanks for commenting!

[@yani4047]

You did a great job but u didn't add the Golgi enzyme Phosphotransferase responsible for transfering Phosphate to Mannose in icell disease.

[@afrotravis]

i like the explanations... i will give u thumbs up... and a subscription

[@stomponstep1989]

arthur travis thank you!

[@bilalfarhan5311]

Thanks for your effort. please Brain can you add to Kartegner syndrome the third triad of dextrocardia too

[@stomponstep1989]

Belal Rawi thanks for the comment! Situs inversus may be important for certain courses and certainly for actual patient care, but I left it out because it is really low yield for the Step 1 exam