Beta Thalassemia; Causes and Types (minor, major and intermedia)

Beta Thalassemia; Causes and Types (minor, major and intermedia)


All right welcome back, so we have been talking about anemia, microcytic anemia, now we’re talking about Thalassemia…in the last video we have talked about alpha-thalassemia (link in description). Today. We’ll talk about beta thalassemia So, Beta Thalassemia is a microcytic anemia, and again symptoms of anemia Tired and pale, pale and tired…sometimes, I have murmur (flow murmer), sometimes I can get angina. also… exercise intolerance, fatigue, Etc. Beta thalassemia is very common in Italy so keep that in mind, okay? So, as you know… Hemoglobin has two alpha subunits, and two beta subunits…good They are called tetramers excellent Thalassemia by definition is a defect in globin chain synthesis good, so this will lead to two things; here you have the globin so Decreased globin synthesis will lead to decreased hemoglobin i.e. anemia Good…what else? when globin chain Synthesis unbalanced hemo tetramers form so for example when alpha is not present beta will form tetramers They are insoluble They will precipitate in RBC’s. The spleen macrophages will recognize that and will cause hemolysis Will destroy these abnormal RBCs. this will lead to… ineffective erythropoiesis Why? -Bone marrow tries to respond to the hemolysis by producing more… red blood cells. However, Globin synthesis decreas; I cannot synthesize Good RBC’s, or sufficient RBC’s. It’s called ineffective erythropoiesis beta thalassemia The problem is in chromosome 11 Do you remember what chromosome was involved in alpha-thalassemia? Correct! – 16 …Okay, how to remember beta and 1? -just draw beta like this: And then draw an 11 like this. Okay, so we can do it better. This is the 11 and then this is the beta, like this. Just any way to remember, okay, it’s common in the Mediterranean, Middle Eastern and Asian population…Please, remember Greece and Italy. Greece and Italy beta thalassemia chromosome 11 Beta thalassemia can be mild or severe Mild anemia usually due to a splicing defect Go back to your Molecular Biology and review this topic. Severe anemia is due to a specific type of point mutation, called: nonsense mutation There is a stop codon. Okay? That’s introduced… Earlier than usual. Stop codons are these as you know this will lead to termination… Of protein synthesis, and in this case the protein is the beta globin -in=protein So, genetically speaking beta thalassemia can be either heterozygous or Homozygous Heterozygous is beta thalassemia minor homozygous can be either: thalassemia intermediate or beta thalassemia major chromosome 11 so, number one beta thalassemia minor there is Increase in the number of microcytic RBCs, of course. Thalassemia is a microcytic anemia. However, in thalassemia There is increased number of RBC’s. Nobody know why!!! That’s interesting so when you have microcytic anemia low hemoglobin, low hematocrit, but, (and that’s a big but) RBC count is a little bit high Iron studies are normal, please suspect thalassemia. Beta thalassemia minor; it’s minor, so it’s either asymptomatic or there is minor anemia So what will happen to the normal adult hemoglobin A? – it will slightly decrease Hemoglobin A2 will increase, hemoglobin F will slightly increase. so, Hemoglobin electrophoresis will show this. Hemoglobin electrophoresis in beta thalassemia minor is… abnormal Contrast that with the minor form of alpha-thalassemia, called: the Alpha thalassemia trait Trait you remember? Trait, where the hemoglobin electrophoresis was completely normal! Alrighty, now the big one; Beta thalassemia major (also known as Cooley’s anemia) so, we start here by a problem in the Beta globin production… Zero; there is none whatsoever; no beta globin production. So what else do we have other than the beta? -Alpha… Alpha globin will form and precipitate forming… Homo-tetramers, and these homotetramers will lead to two things: first in the bone marrow… the RBC’s containing the Homotetramers will die… Earlier before being released… why? – they are not healthy, they cannot survive. So, they die… This is called ineffective Erythropoiesis, as you know. What else will happen to these… homotetramers? – they will precipitate in RBCs, so the Macrophage in the spleen will recognize these Oh, these are ill, abnormal RBCs, let’s kill them!!! :O So, they destroy the RBC’, which leads to hemolytic anemia. Hemolytic anemia? – the kidney will respond by increasing Erythropoietin production erythropoietin will lead to something called… Erythroid hyperplasia Erythroid is the cell line that produces RBC’s and… hyperplasia means increasing the number of cells, so we increased number of RBC’s and… We increase the formation, increased production in the bone marrow… This is called: medullary erythropoiesis Fine. But, I need more, I need more factories to produce more RBC’s, so the spleen and the liver , or the reticulo-endothelial organs will take over. It’s called extra-medullary Hematopoiesis. They will start forming new RBCs Ok, they are working really hard. They will enlarge… “hepatosplenomegaly” Fine, the medullary cavity inn the skull, and in the bones will enlarge. When they enlarge, This will include the skull who give us an appearance on x-ray called hair on end appearance or crew-cut skull Crew-cut-hair skull Also, the maxilla: the maxillary bone will enlarge leading to something called chipmunk facies fine! So, hemolytic anemia…so we need to give the patient blood. Giving them blood? -we will make them dependent on the transfusion or transfusion-dependent This blood contains iron, which will lead to iron overload… Hemosiderosis and secondary hemochromatosis…What else? anemia; hemolytic anemia is destruction of the Hemoglobin, and hemoglobin has heme and globin. Haeme has iron and protoporphyrin. Protoporphyrin will convert to unconjugated bilirubin, goes to the liver to be Conjugated into the conjugated bilirubin Okay, so this increase in unconjugated bilirubin Will lead to unconjugated hyperbilirubinemia and of course jaundice! That’s it for beta thalassemia major…if you understand this slide, you will know a lot of information for your exam ๐Ÿ™‚ Now, the last one: Beta thalassemia intermedia It’s an intermediate form it’s not as severe as major, but it’s also more severe than the minor beta thalassemia So there is an a Co-inheritance with alpha thalassemia trait. so, when you have beta thalassemia intermedia, usually you have also alpha-thalassemia trait fine! Okay, so there is also minor Qualitative defect in the beta globin, so usually we have alpha and beta Remember in beta thalassemia major, we don’t have any beta. So, the Alpha Increased forming Homotetramers. However in this condition. I have also alpha-thalassemia trait I have Deficiency in this alpha globin chains, so I cannot increase them as much I cannot Produce as much homotetramers, so there is less homotetramers Than beta thalassemia major…There is less Hemolysis, and of course, hemoglobin F Will increase since you don’t have beta. What will happen? -Gamma change will form when you have alpha and gamma. This is called Hemoglobin F, the fetal hemoglobin. Okay, that’s it for thalassemia, guys I’ll see in the next video, but please subscribe like us on Facebook and follow us on Twitter Thank you very much

81 thoughts on “Beta Thalassemia; Causes and Types (minor, major and intermedia)”

  1. Thank you so much for the full description of the disease. I have minor thalassemia from my father, born in Portugal, mother is French. I followed recommendation to take iron supplements or increasing my iron diet, I eat very healthy and organic food, no red meat, only vegetables, wild fish and occasionally white meat. Maybe you can bright me with the issue I am experiencing, if I consume a little excess of iron, pills or food, I am getting excessively tire faster than normal (usually I feel a โ€œcrashโ€ around 3.30 pm every day) with iron. I am very active all day long until 3.30pm. What do you recommend to keep me active with energy all day long? Thx you for your time

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  3. If one parent has the alpha thalassemia trait and the other parent has beta thalassemia minor, will the fetus still have thalassemia major? Or is it different because they're on different chromosomes?

  4. It's amazing that modern medicine was capable of figuring all of this out, but of course they can't seem to figure out how to treat or cure it. Then again, they still can't seem to cure much of anything because that would cut into Big Pharma's profits. Can't have that, can we!?

  5. Hello my friend, long time no see.
    I am just thinking, when beta-chain is lacking, shouldn't the alpha-chains combine with delta-chains to form HbA2 instead of tetramers?
    Unfortunately I have yet to come across real patients with beta thalassemia major, sigh.
    Your videos are excellent as always!

  6. you know we are not 1st grade children watching the vidoes , maybe u can try to talk like ur talking with adults

  7. Me n my son have thalassemia intermedia. N my husband has thalassemia minor. I don't know what will be our future.m scared for my son.

  8. Hi i just know from my HP elecro…. That i have Beta thalassemia Trait detected on HPLC. What will consequences of this on my life and what should i take steps now.?? Please guide me

  9. Your hematology videos are so helpful and clear. Thank you, I appreciate them.
    Can I ask you question : you said beta thalassemia can be heterozygous or homozygous And the heterozygous is the beta thalassemia Minor, Hereโ€™s the question, how could it be heterozygous while the disease is autosomal recessive at the same time ?
    This is very confusing to me

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  11. Well anything about science is really fascinating to me but the way you speak and explain this concept let me think you don't love what you say.

  12. I don't get why thalassemia out of all chronic hemolytic anemias is microcytic hypochromic ??
    You'll be much appreciated if you could explain why please.

  13. I'm really thankful. This helped me alot.
    I'm in my pediatrics round and thalassemia is one of my worst topics ever.
    Also my pediatrics' exams are next week so plz wish me good luck.

  14. Bro video is great, content is also great, but the only problem is try to speak little fast and more maturely.

  15. Thanks so much. i have a question .. Why can we say alph thal (Hb H ) resemble beta major ? . in symptoms.. and you mentioned in alph thal. video that " B4 hemotetramers can't be found in BM " Do you mean that hemolysis only happens in Spleen and Liver ?

  16. 1:20 beta chains are less or not synthesised => tetramers 4 alpha chains (they are not stable which lead to destruction of erythroblasts).

  17. As u said in b thalassemia minor RBC high and MCV normal but if MCV. And MCH are not normal I mean less then 80 like 60 what then

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