How 6 Rare Diseases Are Changing Everyday Medicine



sasha was supported by Skillshare right now Skillshare is offering scishow viewers two months of unlimited access to over 20,000 classes for free click on the link in the description to learn more individually rare diseases are rare in the US we usually say that a disease is rare what it affects fewer than 200,000 people in the whole country and in the EU a disease is rare when it affects fewer than one out of every 2,000 people that's not very often but because there are so many different rare diseases experts estimate there are about 7,000 collectively it's not so rare to have a rare disease in fact about 30 million Americans have a rare disease around the same number who have type 2 diabetes so studying them is important in its own right but these sorts of investigations can also reveal larger insights into how our bodies work and because many rare diseases are caused by relatively simple known mechanisms they can also tell us about things that can go wrong in much more common diseases sometimes this even means that researchers can come up with a drug that works for millions of people here are six times research into the most uncommon maladies on the planet have turned out to benefit the masses first up a bone mineralization disorder called hypophosphatemia or HPP in severe cases which affect about one in every 100,000 people patients have soft bones that can easily break and deform many patients are in chronic pain and often lose teeth prematurely and 1/4 experience more than ten fractures in their lifetime the disease is caused by a gene mutation that prevents the body from making the correct versions of the enzyme alkaline phosphatase in the mid-1960s researchers learned that this enzyme regulates the body's production of a molecule called pyrophosphate it's found in blood and urine and prevents the main mineral in our bones from growing without enough of the enzyme the body has too much pyrophosphate so mineralization doesn't happen as well while researchers were working to understand HPP they realized that pyrophosphate might actually have another use – previously they'd found this molecule had a perk it kept bone minerals from dissolving so may it could help patients with osteoporosis a disease of low bone mass that affects around 200 million people around the world scientists then search for compounds that mimicked pyrophosphate and they found that the water softening molecule bisphosphonate did the trick now it's a common osteoporosis drug although they later realized this treatment actually works for a different reason it prevents cells called osteoclasts from breaking down bone because they don't need extra pyrophosphate artificial or otherwise the drug that HPP patients helped give the world won't help them might even make them worse but if nothing else it did change how much we know about bone biology and led to a whole new class of drugs for millions of people next is Gaucher disease which affects somewhere around one in every 50 thousand or hundred thousand people and share some interesting parallels to Parkinson's Gosha is what's known as a lysosomal storage disease that means there's a defect in the organelle in cells lysosomes that digests garbage when that happens the lysosomes can't get rid of the trash fast enough and it builds up in Gaucher this is the result of an enzyme deficiency specifically one called glucose Arab Rossa days.if specializes in breaking down certain glyco lipids which are basically fats with the sugar attached to them so without enough of the enzyme they build up especially in the liver spleen and bone marrow which produces blood cells as a result people with the disease often don't have enough blood cells which can make them more tired and more prone to bruising and bleeding they can also get enlarged spleens and livers on rare occasions Gaucher patients also develop symptoms like tremors and slow movements similar to Parkinson's under a degenerative disorder that famously affects people's ability to move initially scientists didn't make much of this then they noticed something surprising with the relatives of Gaucher patients those who carried the mutation that causes the enzyme deficiency were more likely they get Parkinson's too in fact a huge genetic study in 2009 revealed that around 7% of participants with Parkinson's had a mutation in that gene the most for any single gene and genetics a finding like that for a multifactorial disease like Parkinson's is huge now scientists are working to figure out what it means one possibility is that not having enough of that enzyme prevents cells from breaking down alpha-synuclein proteins these can get MS folded in the brain and are thought to be one of the main causes of Parkinson's that's unlikely to be the whole story but it could be important for a subset of cases scientists are hopeful that studying this enzyme and lysosomes in general may lead to a new understanding of Parkinson's and possibly to new treatments for the disease and for those with Gaucher too but the fact that Gaucher has already helped identify the biggest genetic risk factor – the second most common neurodegenerative disease it's a pretty big deal speaking of lysosomal storage diseases as you do a scientists are finding that another one called niemann-pick might help us combat Ebola virus technically and fortunately Ebola hemorrhagic fever is also a rare disease but that could change at any time with an outbreak I could 2011 researchers were studying the virus to figure out how it was getting into cells they knew it used a certain glycoprotein to do it but they didn't know what on our cells it was targeting so they set up a screen testing the Ebola glycoprotein on a series of different cells each of which at one mutation wierdly a bunch of the cells that kept the virus out had a mutation in a gene called npc one which makes a protein that helps shuttle cholesterol around inside cells this is the same gene that's mutated in niemann-pick disease type C or NPC which affects around one in a hundred and fifty thousand people patients with it end up with buildups of cholesterol inside neurons which can cause dementia at a shockingly early age for that reason it's sometimes called childhood Alzheimer's thankfully there are some treatments for it but the disease itself could also help treat thousands of others because when scientists tried to infect cells from NPC patients with Ebola they couldn't the mutation was keeping Ebola out the fact that Ebola targets NPC 1 explains part of why it's so deadly it's in all cells so the virus can target any cell in the body not just a few like most viruses now researchers are using this knowledge to create new ebola drugs if they can make molecules that block the NPC one protein they may be able to prevent people from getting infected sometimes rare diseases are helpful to scientists because they can confirm that what they've seen in lab animals also applies to humans that's what happened with an extremely rare condition called congenital leptin deficiency as the name implies people with this disease don't make an lepton a hormone that fat cells produced to tell the body to stop eating as a result they're constantly hungry and eat way too much food these people become obese very early in life usually within months of being born we know of about 30 cases now but for a long time we didn't know the condition existed and that became important because for decades scientists have been using a mouse with mutations in its leptin genes to study type 2 diabetes mice become very obese and if they have the right genetic background they develop diabetes quickly making it easier to study the disease in the lab years if mice experiments suggested that leptin might be important for our understanding of obesity but no one was really sure how relevant it was to people that changed in 1997 when researchers identified two severely obese children who shared the same mutation in their leptin genes they made far less leptin the normal showing that this hormone was a key player and how our bodies regulate the amount of food we eat and how much fat we put on like with a niemann-pick and Ebola some rare diseases it turns out come with perks in the case of something called laron syndrome those advantages are potentially life-changing for the rest of us if we can figure out how to mimic them people with other owns are very short under 1.4 meters tall because of a mutant growth hormone receptor even though they make plenty of growth hormone and their bodies can't use it normally so they never get very tall and their limbs are short it's a unique form of dwarfism and fewer than 400 cases have been diagnosed worldwide the surprising thing is even though these people are often obese they have normal blood pressure and they seem impervious to diabetes and cancer in one village in Ecuador where the condition is common just one person and a sample of 99 was diagnosed with cancer in contrast cancer kills about 20% of relatives of people with laron syndrome the secret both to their disease and their superpowers may have to do with something called insulin-like growth factor 1 or igf-1 for those with lorentz growth hormone receptors don't trigger cells to make igf-1 and since that's what tells the body to grow not having it around explains their short stature but igf-1 is also thought to contribute to uncontrolled growth in some cancers so limiting it in adults might be a good idea so far scientists have even found that mice missing the growth hormone receptors make less igf-1 and live longer and are less diseased now they're working on ways to get the same results with a pill or supplement finally if going cancer and diabetes free isn't enough there's a rare blood clotting disease that's revealing a lot about aging too in plasminogen activator inhibitor type 1 deficiency patients lack a specific blood clotting proteins so clots break down faster than they should which obviously isn't great but last year scientists studying an Amish community in Indiana where the condition is more common found that carriers of the disease live abnormally long around ten years longer than their peers they also have fewer cases of diabetes these carriers make less of the protein than normal but fortunately don't have any problems with clotting it's still preliminary but researchers in Japan are now testing a therapy that partially blocks the clotting protein if it works this could be an amazing outcome of studying something that affects just a few hundred people digging into rare diseases doesn't seem to make a lot of sense if you're trying to do the most good for the most people but as these examples show because of our shared biology it's often remarkable what we can learn it's been the spark behind osteoporosis drugs a key part of our understanding of Parkinson's and might even let us live longer healthier lives so so far our knowledge about these rare conditions looks like it's giving back many times over so we're trying something a little different this week it's extremely important to me and the rest of the scishow team to make sure that one scishow is high quality content and two that it remains free to anyone who wants to see it of course our patreon community is a huge part of those two missions but another part that we don't talk about as often is Skillshare we're grateful and excited that this entire week of scishow videos is made with support from Skillshare which helps us keep scishow free for everyone but even when Skillshare isn't helping to pay for scishow the scishow team and I still use it to get better at our jobs and make videos that we hope you'll like so I have a story I started using a piece of graphics editing software a very long time ago that is now basically useless so I have started to take a Photoshop class to refresh those skills so that I can export in file formats that 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26 comments

  1. I’d love to see a video on rare diseases with neat backstories. Not necessarily ones that are helping find cures for other diseases, but more ones with other interesting stories to them. For example, I live with CRPS type II, a rare degenerative neurological disorder. Except it doesn’t attack the Central Nervous System directly. Nope, it likes to destroy the Sympathetic Nervous System, which is how the most common form of the disease (now known as CRPS type I) got its original name of Reflex Sympathetic Dystrophy. CRPS type II, on the other hand, was actually the first form identified and it was originally known as Causalgia. And it’s the history of Causalgia where things get interesting. It was discovered during the American Civil War. Yet, despite its initial discovery and the craziness that followed (they tried to amputate effected limbs which failed miserably), there are still no approved treatments for it in the vast majority of countries.

    It’s cause is also very interesting. It’s triggered by some form of trauma to the body (the severity of the trauma involved draws the line between the two types). Type I, which accounts for 90% of patients, can be caused by something as minor as a stubbed toe and it’s onset can be delayed by up to several weeks. Yet when the disease finally starts, it starts instantly, straight into the deep end with excruciating, nearly intractable pain. A rather common story amongst patients is, “yeah, I broke a small bone and everything was fine. Then a few weeks later, I woke in the middle of the night, screaming in agony because the sheet was touching me.” Despite this overly dramatic onset, it still takes an average of 6 years to get diagnosed.

    Both forms of CRPS combined are rather rare, with 1 in 5,000 people thought to have them. (For reference, in the US, rare is fewer than 1 in 2,000 people.) But CRPSs claim to fame isn’t its scarcity. Rather, it’s the symptoms. It’s the most painful chronic illness known to science. On a 50pt scale, a broken bone is about a 20, severe spinal problems are a 30-40, cutting off half your foot with a lawnmower is a 41, and CRPS is a 43. It usually effects only 1 or 2 limbs, but it can spread to effect all extremities and some patients even have it in their abdomen, plus it can damage internal organs (usually the heart).

    Other common and interesting symptoms include changes in skin color to white, red, blue, or purple (I even turn polka dotted, which is super entertaining) often accompanied by changes in skin temperature, muscle spasms, muscle atrophy, involuntary movements, osteoporosis, edema, hyperalgesia, and severe allodynia. That’s on top of the pain of feeling like you’ve been dipped in gasoline and lit on fire, your bones being crushed with a pickaxe, and/or the feeling of being wrapped in barbed wire.

  2. Fascinating as always.

    Chronic Illnesses & diseases are a personal interest of mine, partially because they're intriguing, but primarily 'cause I have the neurological disease Fibromyalgia. It's not a rare condition, with it affecting approximately one in every twenty people (in western countries), or about 5-7% of the population. Despite this, it hasn't had a great deal of funding being put into research, with the majority of studies concerning it being pilot studies using very small groups of people.

    It's etiology has remained elusive, though in recent years it has been clarified to be a both a neurological & neuroendocrine disease (it was previously considered a rheumatoid condition due the heightened presence of several pro-inflammatory cytokines), through improved fMRI techniques. That it overlaps multiple medical disciplines has proved to be a hindrance to both scientific research & clinical treatment – though treatments like Lyrica/Ketamine for the Neuropathic Pain, Cymbalta for the "Fibro-fog", Naproxen for the inflammation & hormone treatments for the HPA Axis dysfunctions have certainly reduced the symptoms, and increased the quality-of-life for sufferers.

    Definitive research into the specific genes that cause Fibromyalgia have been sadly lacking (it's been known that it is a hereditary condition since at least the 1990s – especially in people with Mediterranean ancestry). With it occurring in such a significant percentage of the population, there is the implication (thanks to evolutionary genetics) that the mutation causing it has improved the survivability of people in the distant past. Why it would cause such a myriad of terrible symptoms in people living today is a puzzle – one that perhaps would also lead to advances in research that could benefit people with other illnesses, like those you mention in this video.

  3. Support your friendly neighborhood Zebras by researching Ehler-danlos syndrome! It's a rare condition that needs a lot more awareness, and in-depth studies done on how to better treat it.

  4. SciShow is one of this one’s longest-subscribed channels on Youtube – high quality in production values (audio is particularly appreciated), and high quality content. Far more likely to trust SciShow than some of the clickbait alternatives out there. Live long and upload often.

  5. best feeling when you randomly find out about stuff you didn't even know existed, every morning on your pocket supercomputer, laptop, or smart display.

  6. According to the book the compas of pleasure, actually lepton production is not the problem most of the time, but lepton insensibility, patients don't have enough receptors for lepton so they keep eating.

  7. I have a rare autoimmune disease called mast cell activation syndrome, I’m hoping I can get my doctors on board with studying me during my pregnancy because there’s not much research or information on people with mast cell disorders who become pregnant

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