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Summary

This session will dive deep into the world of DNA, exploring its structure, functions, and crucial role in human genetics. Attendees will learn about DNA structure, nucleic acids, and genes, as well as how different types of mutations can lead to genetic diseases. Other topics of discussion will include the effects of mutations on amino acid sequences and the role of the CFTR gene in cystic fibrosis. The session will look at a range of factors, from point mutations and their impact on genotype, phenotype, and genetic disorders, to chromosome mutations. The speaker will explore the different types of amino acids and their roles, and examine conditions such as Beta Thalassemia and Down Syndrome in detail. Attendees will also learn about chromosomal structures, abnormalities, and their implications for diagnoses, and will explore how drugs impact DNA synthesis. Join this session to expand your knowledge on DNA and its complex but intriguing role in human biology.

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Description

UKMLA Revision held by Elham Sahibzada, with a degree in Molecular Biology.

The session will be 1 hour and 30mins with UKMLA style questions at the end.

Explore relationship between the processes involved in gene and chromosome behaviour, gene expression and the activity of cells, and to be able to apply this understanding to clinical practice in the future as well as part of the UKMLA Revision.

Learning objectives

  1. Understanding of DNA Structure: By the end of this session, learners should be able to explain the basic structure of DNA, including the role of acidic bonds, phosphodiester bonds, and phosphate groups in giving DNA its polarity.

  2. Comprehension of Genes and Mutations: Learners should be able to define what a gene is, the genotype, phenotype, and understand the concept of mutations. They should gain knowledge on silent and harmful mutations and their potential impact on the individual.

  3. Presentation of Specific Genetic Diseases: Learners should comprehend specific genetic diseases such as cystic fibrosis and beta thalassemia - how they occur, their symptoms, and their impact on the affected individual's health.

  4. Understanding Replication and its inhibition: Attendees should understand the stages of replication and how certain drugs can inhibit replication, including specific examples such as CISplatin.

  5. Knowledge of Chromosomal Structures and Abnormalities: By the end of the session, learners should have gained a thorough understanding of karyotyping, chromosomal abnormalities like polyploidy, unemploy, Trisomy and various genetic disorders. This should also include understanding the role and features of sex chromosomes and their abnormalities.

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The following transcript was generated automatically from the content and has not been checked or corrected manually.

The slide where I was actually at. So the DNA itself is a ribonucleic acid with black acidic bonds um within the nucleic acid itself. But between each of the nucleotides, you have phosphodiester bonds. But because of the phosphate group within the DNA strand, it actually becomes negatively charged. And because of that reason, it has has that polarity. So a section of the DNA strand that kind of calls for the phenotype of an individual is obviously a gene, which kind of is the genotype of the individual. So to protect the DNA, it grows around a histone protein. And the coiling of that DNA is what sort of creates that minor and the major bruise of the strand itself. So, like I said, the DNA sequence will code for a certain geno genotype, which will code for a specific phenotype. But there may be certain factors that could potentially damage that DNA strand um thereby leading to spontaneous mutations. So sometimes those mutations might be silent whereby it has no effect on the individual, but sometimes it could also be quite harmful on the patient where it could lead to genetic diseases, which we will go over later on as we progress through the session. So let's have a look at point mutations which are the main cause of DNA mutations. So you've got a range of point mutations here. So I'm just going to move my camera across. So you have your transition mutation, which is a particular type of point mutation. This is where you have a primine converting into another type of primine or could have a purine converting into another type of purine. So they are from the same category if it converts into a different category. So for example, cidine into a purine, um that's called transversion. So it's still an ointment, just a different type of o muation. But with these point mutations, you could potentially just have substitution where you substitute one base with another base or add an additional base which is insertion or simply just delete it. But you have to bear in mind that once these mutations occur, it has an impact on the amino acid sequence. So either it could be a silent mutation like I said, where it has no impact on the individual or it could be a nonsense mutation where the mutation that has arised gets converted into a stop codon. But if it gets converted into a different type of amino acid, it's referred to as a missense amino acid. So these are pretty much the main types of amino acids mutation that could potentially arise. So, so if you have a look at cystic fibrosis. Cystic fibrosis is probably one of the main types of genetic mutations that could arise. Um And that's a mutation in the CFTR gene. And it's in particular, a genetic mutation that affects the lungs primarily or the digestive system. It's what happens in essence in here, in a nutshell is that the protein that is involved in the transport of the chloride ions across the cell membrane, that protein gets altered, whereby it leads to that dysfunction of the thick salty um mucus within the lungs and other organs, which kind of causes a range of complications because you have that accumulation of the chloride ions within the mucus itself. So, if we have a look at, in terms of the respiratory system, it could lead to things like persistent cough or a very thick presence of mucus, um prolonged lung infections as well. So things like pneumonia or bronchitis or even things like shortness of breath or wheezing could happen. It could in essence impact the digestive system too where the stool might be quite bulky or greasy. Um or we could potentially have some sort of bowel obstructions. So there's a range of symptoms associated with just one impact of a gene mutation. So, what you can see on the slide here is that the um mutation actually arises in the region of 508. So it's completely deleted. So, alongside of mutations within the coding regions, um the DNA strand also have to kind of be aware that not every single section of the DNA strand is coded, there are sections of the DNA strand where it's not coding pretty much for anything at the time frame. And that's referred to as your inr. And sometimes you could have mutations outside those coding regions as well. In particular, your splice donor and your accept toys. And in particular, if we have a look at beta thalassemia with beta thalassemia is a cryptic splice site mutation. And it it is a genetic disorder which is categorized by a reduced or absent synthesis of beta globulin changes in the hemoglobin itself. And this reduced synthesis is often caused by mutations in the HBB gene. And that pretty much codes for the beta globulin protein itself. And these mutations impact the splicing which will lead to that abnormal Mrna processing. And then as a result of that, it leads to that reduced or nonfunctional beta globulin protein production. And we will go over um beta thalassemia in a lot of detail at a later stage. So when these mutations appear and they get replicated within the cell, we can potentially inhibit them using certain drugs that target certain sections of the replication. So within the replication stages, you've got initiation elongation and termination and each certain type of medication will pretty much impact those particular stages. So for example, CISplatin, which is a chemotherapy agent is going to inhibit that DNA synthesis. And the way it's going to do that is it going to sort of prevent the cross linkages of the DNA strand? And as a result, it leads to apoptosis and DNA damage as a whole in essence. So that's just one example, but you can see the other two on the screen um that are also used, but they aren't lately as used as much in comparison to CISplatin. So let's have a look at chromosomal structures. So, carer typing serves a sort of vital diagnostic tool across various medical specialties, providing that sort of insight in genetic health and abnormalities. So, indications for karyotyping sort of include the prenatal screening for chromosomal abnormalities, investigation of birth defects, malformations, assessing sort of sexual development abnormalities such as Klinefelter syndrome, which again, we'll go over in a minute and also things like diagnosing infertility causes and simply just helping with the management and treatment of um cancers such as leukemia. So a carrier type is actually an image of an individual's chromosome set that you can see on the screen here. So it's pretty much this um and that is typically presented in metaphase or prometaphase of a chromosome and these chromosomes are then arranged in pairs in a karyogram. So the karyogram is actually the image um which highlights the size position and the centromere location of each chromosome, which again is actually very, very important when it comes down to chromosomal mutations. Um things like translocation, how they fuse So I've put an image up on here where the position of a centromere are and what they are referred to as. So with chromosomal abnormalities, just like DNA abnormalities, you can get all sorts. So you have polyploidy, which is probably the main one and is referred to as having two or more sets of um Chromos. It is a rare condition. So sometimes or no, actually sometimes in a matter of fact, all the time is pretty much lethal um in humans. But tetraploidy is a characteristic whereby the Chromos encountered is by four times. As an example of a polyploidy, then you have endoloop bloody. However, is the duplication of the whole entire genome within the whole normal chromosome itself. Um And as a result, the sort of fetus has doubled the amount of genomes as it should. So with tetraploidy, often it stems from polyspermine and it can lead to things like miscarriages due to that abnormal chromosomal um composition with unemploy. On the other hand, um it denotes the abnormal number of chromosomes unlike polyploidy, which is the complete set. Um and this is pretty much commonly associated with Trisomy, which we'll go over in a bit and it does exhibit a risk with maternal age. So as maternal age increases, the risk of unemploy also increases. And the primary course of unemploy is actually the non disjunction of chromosomes during meiosis. One in particular, in prophase, one which leads to that unequal distribution of chromosomes into the gametes. And this process can lead in homos mutations as a result of that. For example, you have the Robertsonian translocation which can produce unbalanced gametes leading to monosomic or trisomic cycle. Um You also have the Philadelphia chromosome, which is the fusion of two sections of the genes which will lead to chronic myeloid leukemia and understanding these chromosomal abnormalities are actually very crucial for diagnosis and management of associated genetic disorders. And once we've understood them, we can actually help target therapies and improve patients outcomes once we understand what genes are being impacted. So with regards to the polyploidies, you have got the three triz in him. Now, with the three trisomies, you have got the Down syndrome, which is probably the first one. and that's probably the most viable one out of the other two. So you have the addition of chromosome 21. And with Edward syndrome, you have the addition of chromosome 18 and Trisomy have the addition of chromosome 13. So the way I have written it down is pretty much the way a car type should be written down. So you should write the total number of chromosomes along with the um sex chromosomes. And if there is an addition of an additional chromosome, you should also include that. So I've put up a sort of characteristic differentials of the three types of trisomy that should help you visualize um the sort of key features within the three So with Down Syndrome, they have that grow failure, they have that sort of flat back of the head, abnormal ears. Whereas with the Trisomy e they do have overlapping fingers, club feet, which is that prominent sign to show Edward syndrome. And low set is whereas pals, the significance here is the cleft lip and the sort of small head and also they have clenched fits, fists, sorry. So not some differences, but you can have a look at the other differences as well in your own time. So if we have a look at sex chromosome unemploy with sex chromosome unemploy, um again, there are genetical conditions categorized by abnormal number of sex chromosomes which can determine an individual's sex. Typically, humans have two sex chromosomes, X and Y. However, in a sex chromosome and employs, there are either an extra or a missing sex chromosome which will lead to a variation in sexual development and associated health effects. And the common ones I have actually listed on the side here. So you have Turner Syndrome where they only have a single X, you have the triple X syndrome. So it is what it is on the 10th. So three Xs Klinefelter syndrome where you have an additional X chromosome and you have the X yy chromosome where they have an additional Y chromosome. But the thing is is that us as humans, we are able to tolerate a additional sex chromosome rather than an additional autosomal chromosome. And that goes down to the fact that we have something called the X chromosome inactivation. So the X chromosome inactivation is the lionization. In other words, whereby you have a transcriptional silencing occurring just randomly in one or 22 chromosomes of the X. And that will actually determine the female's um development in essence. So what you have here is your bar body and your bar body in essence, is that inactive chromosome that we were referring to and is pretty much on the sides on the corners here. So obviously, the middle is going to be what the nucleus, but you have the side here as your bar body is. So you've got your Turner syndrome if we have a look at each of those um sex, um chromosomal disorders in a little bit of detail with Turner syndrome. Um it occurs when a female only has like I said that one X chromosome instead of the usual two. So the features usually include your short stature, infertility, the web neck, heart defects, learning difficulties and is the primarily cause of the absence of menstruation in females. Now, by having a single X chromosome, it poses a challenge because not all of the genes on the inactivated chromosomes are completely silenced. So, in patients that have Turner Syndrome, um where they lack that chromosome, it poses a lot of sort of health issues due to that chromosomal abnormality because we were supposed to. Well, these patients are supposed to have the pseudoautosomal regions on the X or the Y chromosome. Um but because of the absence of them, it is what creates um all of these sort of key features that you can see with patients with 10 syndrome. Then you have got Kleinfelter and triple X. So with Kleinfelter, you have that extra X chromosome and that results in male hypogonadism. So that sort of reduced function of the testes, infertility, they have that tall stature, gynecomastia, which is the enlarged breasts. And also again, with any other sex difficult uh chromosome mutations, you have that sort of learning difficulties as well. So with the triple X syndrome, it often involves females having the additional or third X chromosome. Now, most individuals with this syndrome are phenotypically normal and they may not actually exhibit any sort of physical symptoms. However, they might experience the learning difficulties, delayed speech language development, delays or even tall stature. So that's something to kind of bear in mind. So, another type of chromosomal mutation is your translocation mutation and this is where your chromosomal rearrangement happens. So you have your two acentric mutations. So sorry, two atraric chromosomes, what they will do is they will fuse near the centromere. And what will happen is what you can see is it will create one larger chromosome and one smaller chromosome. And this translocation can actually lead to an individual having potentially normal number of chromosomes, but it has altered genetic makeup due to the fact that the chromosomes have been pretty much rearranged. So the Robertsonian translocation can actually cause things like reproductive issues. As carriers may produce the gummies. But with a unbalanced chromosome numbers, it could also potentially lead to miscarriages or offsprings with chromosomal abnormalities as well. So with Philadelphia chromosome, which we have seen earlier on, it is again a genetic abnormality resulting from again a chromosome nine and 22 fusing together. And as a result, you'll get a shorter chromosome 22 also known as your Philadelphia chromosome. And this translocation results in the fusion of your breakpoint cluster region, which is your BCR on chromosome 22 with the alberson, which is your ABL gene on chromosome nine. And this fusion is the fusion that I was referring to earlier on, which is your BCR ABL um fusion. And this produces a active tyrosine kinase enzyme. And that plays a major role in the pathogenesis of your chronic myeloid leukemia patients. So, by having these targeted therapies such as tyrosine kinase inhibitors that have been developed, we can potentially inactivate this protein and inactivate this enzyme to sort of improve the outcomes of these patients that have this particular disease. So what I've put here is some screening programs within the NHS that have been used throughout and are still being used. So you've got the screenings offered during pregnancy once the newborn has come on and you have got your precancerous cell changes in the body as well. Um Those are relatively not new, but they have come around more predominantly in the last few years. And what it does is that it detects or screens breast and cervical cancer in women an earlier stage as well as bowel screening. So for bowel cancer for both men and women, and what we'll do is we'll go over each of those sections in a little bit more detail. So let's have a look at screening in newborn. So screening in newborn. So with the newborn blood spot, also known as your heel prick, um it involves a collection of your small of the baby's small blood sample from the heel within the first five days of birth. And this screening pretty much helps to sort of detect any genetic metabolic congenital um disorders. So it kind of allows that prompt innovation, um treatment prevention to minimize any sort of health problems later down the line. And what I've done is I've listed the main ones that the heel prick um test actually looks out for. Now you've got your newborn hearing screening and that's pretty much a in a nutshell, a simple test conducted surely again after birth. And that is to sort of identify the infant's risk at things like hearing loss. It typically involves measuring the baby's response to sound, using specialized equipment to detect any auditory signals. Again, detection at this early stage helps with the support of things like language and communication development. Then you have the newborn physical examination. The examination is pretty much a routine assessment conducted again after birth. And that's simply to evaluate the baby's overall health in general, um including things like vital signs, appearance, physical features. And it in essence, helps to sort of detect any abnormalities or potential health concerns at an earlier stage. So we can then sort of facilitate any treatment accordingly if that is required. Ok, so then you have screening in pregnancy. So the first one is your maternal health screening and it involves assessing pregnant woman for potential risks and providing that appropriate interventions to ensure that sort of wellbeing of both the mother and the baby. So, high risk mothers may involve further interventions such as glucose tolerance tests if they have things like gestational diabetes or low dose aspirin to prevent preeclampsia and referrals for specialist services for mental health disorders. Additionally, blood groups and rhesus factor testing is actually also conducted um to determine if the mother or the baby does require an anti immunoglobulin administration. So these screenings are there to sort of mitigate risk and promote the optimal maternal and fetal health outcomes as a whole. So you also have your screening for infectious diseases during pregnancy and that typically occurs within 10 weeks of gestation. And it focuses on detecting three key infections, hepatitis B HIV and syphilis. Um additionally, immunity to other infections, diseases like rubella is also checked, which could have been sort of acquired from previous sort of immunization or previous sort of infections. And the screening allows the early detection and treatments for those infections. So then you're in a way preventing that vertical transmission from the mother to the child. So ensuring the health and the wellbeing of the mother and the baby. So next, you have your 20 week pregnancy scan, which provides a detailed examination of various fetal structures, including the bones, the heart, the brain, spinal cord, face, kidneys and abdomen. During the scan, you have a sonographer which is going to evaluate all of the 11 rare conditions. Um aiming to detect any abnormalities or developmental concerns at an earlier stage. And it's pretty much a comprehensive assessment which ensures monitoring the baby's health as a whole to identify again any sort of early abnormalities. But you could also have the noninvasive prenatal testing. So, if we have a look at the combined test, which is usually administered between 10 to 14 weeks of pregnancy, it integrates the new co translucency measurements within the serum biomarkers for pregnancy associated plasma protein A and your beta has and all of these will assess your risk factors for triazine 2118 and 13. So it pretty much offers that comprehensive evaluation of the fetal chromosomal abnormalities at an earlier stage of pregnancy. But you could also have the quadruple test um in the second column which is typically conducted between 14 to 20 weeks and entails a blood test examining for alpha fetoprotein and also beta HCG as well as inhibit a levels and unconjugated estriol. Now, what this test does, it mainly focuses on Down Syndrome alone. So, while it is less accurate compared to the combined test, it does serve as an additional tool to test for Down Syndrome at a later stage of pregnancy. So in essence, both tests actually play a crucial role in guiding clinical um decision making and offering that sort of appropriate counseling for the parents. If let's say a mother has or is late for a blood test, what we can then potentially offer is a midpregnancy scan. It might not be as accurate as the combined AWK quadruple test. But it can potentially give us a overview of things like trazine 13 and 18. It just doesn't show us trazine 21 in this particular thing. So you have your prenatal diagnostics. So your prenatal diagnostics, we obviously need to gain the DNA uh fe fetal DNA, sorry from the three that I stated him. So your amniotic fluid cells, your villous biopsies, all the fetal DNA in the blood. So, with regards to your prenatal diagnostics, it involves a range of medical tests and procedures performed during the pregnancy to assess the health of the fetus. And these diagnostic techniques are aimed to potentially detect again genetic chromosomal or developmental abnormalities in the unborn baby. Again, allowing that early detection or intervention if required So, if we have a look at the chorion villus biopsy, it is a prenatal diagnostic procedure which is performed between week 10 to week 13 of gestation. And during this procedure, a sample of the placental tissues which is referred to as your chorionic vs are obtained either trans or transabdominally under a guidance of a ultrasound scan. And this tissue sample is then analyzed for chromosomal abnormalities or genetic disorders um to see if there's any information with regards to the baby's health. Whereas the next one is your amniocentesis. On the other hand, and that's usually conducted slightly slightly later on between week of 15 to week, 20 of gestation. And that pretty much involves inserting a very, very thin needle through the abdomen into the amniotic sac that you can see on the screen. And from there, we'll draw a very, very small sample of amniotic fluid. The fluid then pretty much will contain fetal cells which are examined for genetic conditions, chromosomal abnormalities and other fetal health conditions that we can see. So as an overview, these two prenatal diagnostics are actually very important tool for enabling healthcare providers to kind of provide the right management, right? Counseling of the baby and the parents. Ok. So let's have a look at hemoglobin and myoglobin. So, hemoglobin and myoglobin are two crucial proteins involved in transport of oxygen within the body. Hemoglobin is primarily found in erythrocytes. They have a half-life of around 100 and 20 days and it facilitates the transport of oxygen um from the lungs to the tissues and to other organs. It has that sigmoidal oxygen dissociation curve that you can see on the screen here, which will pretty much indicate the cooperative binding of an oxygen molecule, which will allow efficient oxygen delivery across varying oxygen tensions. Whereas myoglobin is actually found predominantly in muscle cells which serves as a oxygen reserve. So it releases oxygen to muscles during periods of increased demand. Unlike hemoglobin, myoglobin, kind of exhibits that hyperbolic oxygen dissociation curve, which kind of indicates a more simpler non cooperative binding of oxygen. But both proteins contain iron which binds to oxygen via the proximal histidine residue. Um Additionally, you've got the Haldane effect, which describes the phenomena where you have the deoxygenation of the blood which enhances its ability to carry um oxygen. So let's have a look at some of the pathologies associated. So, methemoglobinemia is a condition where you have met hemoglobin um formed. And that's a form of hemoglobin where you have oxidized iron. So instead of having the usual juice form of iron, so instead of having fe two plus, you have the oxidized, which is ee three plus. And this alteration reduces hemoglobin's ability to kind of bind and release oxygen effectively where as a result of that, it actually leads to tissue hypoxia. So an example could also be when carbon monoxide is present, it competes with oxygen for the binding site of hemoglobin. So, carbon monoxide has a higher affinity for hemoglobin than oxygen. And as a result, um you end up forming carboxyhemoglobin. And this results in the displacement of oxygen from hemoglobin leading to the impaired oxygen transport to tissue. Additionally, carbon monoxide alters the binding of myoglobin. Again, oxygen binding protein molecules in the muscles further sort of exacerbating the tissue hypoxia. And because of that, you have carb poisoning, which leads to severe sort of consequences, things like tissue damage, organ failure, even death. And one of the key sort of signs that you could see is the bright cherry color that you could see on the skin. Ok. So let's have a look at a thalassemia. So bef oh sorry, before we go on to thalassemia, I actually wanted to talk about the bore effect. Before we move on to thalassemia. The bore effect is actually a physiological phenomena that describes the relationship between not just Ph but everything that you can see um on the side here. But let's have a look at Ph. So it shows the relationship between Ph and the binding and the release of oxygen by hemoglobin. So what it states is that as Ph decreases, it becomes more acidic, the hemoglobin's affinity for oxygen decreases, promoting that oxygen release to tissues. Alternatively, as Ph then increases, obviously, because it becomes more alkaline hemoglobin's affinity for oxygen then increases facilitating that oxygen binding. And this kind of effect kind of ensures that you have that supply and demand being met of oxygen. So now we can move on to thalassemia. So thalassemia is again a group of inherited blood disorders that we have spoken about slightly earlier on where you have that reduced or absent production of hemoglobin. The protein response, which is pretty much the protein responsible for the oxygen being carried in your red blood cells. And it sort of results in the mutations of the genes for producing either your alpha or your beta ge genes of your hemoglobin. Now, thalassemia can actually be classified based on what chain is predominantly affected. Either if it's your alpha chain is referred to as alpha thalassemia. If it's your beta chain being impacted, it is beta thalassemia. Um and these genetic mutations lead to a abnormal hemoglobin production where you have symptoms such as anemia, fatigue organ damage um being present. So, thalassema inheritance is usually autosomal recessive um pattern, which means that in a individual has to inherit two mutated copies of the gene. So one from each parent to actually develop the disorder carriers. On the other hand, have only one mutated copy and they tend to be asymptomatic but they can pass on their mutation to their offspring. So if we have a look at alpha thalassemia, which is the one in the middle hip, it is a genetic disorder. And what happens is that you have a malformation of your alpha globulin chains and you can actually categorize um alpha thalassemia in 34 different categories actually. So you have your sinus carrier and individuals carry only sort of one mutated alpha globulin gene. But because it's a recessive um disorder, you need both copies and as a result, they become asymptomatic, then you have the alpha thalassemia trait. And in this form, the individuals actually inherit two mutated alpha globulin genes. So one from each parent, which will then lead to mild anemia. And often they don't actually show too much significant signs. But um the next stage is your hemoglobin h disease. And this condition actually results from the inheritance of your three mutated alpha globulin genes, which leads to a moderate to severe anemia and possible symptoms such as fatigue, pale skin or even jaundice. And then the last one for alpha thalassemia is your hydrops fetalis. And this is probably one of the severe forms of alpha thalassemia. And what happens here is that all four of your alpha globulin Kines are mutated, leading to that lifethreatening anemia and the fluid build up in the body before birth. Often this will result into stillbirth or early death after the birth of the child. So, the severity of the alpha thalassemia actually depends on the number of mutated globulin genes inherited. Um but we will go over the management of both alpha and beta in a bit. Whereas with beta thalassemia, which is on the far right again, is a dysfunction in the beta globin chain. So you have beta thalassemia minor. So individuals with this form of inheritance only have one mutated beta globulin gene from one parent. Again, here you have mild anemia shown but other symptoms might potentially be absent in this case. Then you have beta thalassemia intermediate. This type results from inheriting two mutated betaglobulin genes leading to a moderate to even severe form of anemia. And the symptoms can actually range from mild to moderate and actually may require at this stage some sort of blood transfusions. But you have thalassemia major and individuals with this severe form inherit two mutated beta globulin genes which results in that sort of profound anemia that requires constant regular intervals of blood transfusion for their survival. And without this treatment, um it actually becomes very, very dangerous for these patients. So if you have a look at the management for thalassemia, it involves a multifaceted approach aimed at sort of pretty much addressing the symptoms, trying to prevent complications in trying to improve that sort of quality of life for the affected individuals. But the treatment could include things like blood transfusion. So the regular blood transfusion that we just spoke about help to sort of maintain the hemoglobin levels. In an individual with moderate to severe forms of thalassemia, you could have iron chelating therapy. Now, the reason why you would have iron chelating therapy is because when you're having that sort of repeat blood transfusions, it can lead to iron overload in the body. So, by having this therapy, you're kind of removing any of the excess iron and preventing that organ damage. But at the same time, you also need to give these patients folic acids which will help with the red blood cell production and you can either prescribe them or if they could potentially apply it over the counter. Another one is bone marrow transplantation. So for individuals with severe, so this is only for severe thalassemia. Um and dies if they're eligible, they could have a bone marrow transplantations which could potentially provide that cure of trying to replace the faulty sort of stem cells with healthy stem cells to produce that red blood cells. But there are complications with thalassemia that could potentially arise. So, like we spoke about was iron overload and that could pretty much damage um the heart, the liver, the endocrine glands or you could have um anemia related symptoms. So things like, you know, fatigue, pill, skin, um shortness of breath or even bone abnormalities. So, thalassemia can impact bone health leading to that skeletal deformities and in risk of fractures. So, these are some of the complications and I've listed the rest on the screen for you guys to have a look at. Um So let's have a look at sickle cell anemia now. So sickle cell anemia is a hereditary blood disorder and it is a point mutation again um in the beta globulin gene. However, this is where you have your glutamic acid being replaced by your valine um amino acid in position six of your betaglobulin chain. And this substitution mutation alters the structure of hemoglobin completely and it causes the cells to adapt that sort of Cres like structure. And this inheritance again is autosomal recessive, which means that an individual again must have two copies for them to actually develop the disorder. It tends to be more prevalent in the African Afro Carribbean descent, as well as certain Mediterranean countries. Um things like the Middle East and India. So, although um individuals with sickle cell anemia initially might be asymptomatic, they could be predisposed to episodes of sickle cell crisis and these sickle cell crisis have to be sort of managed as soon as possible. The first one is your vasoocclusive crisis and this is when the sickle cell shapes of the red blood cells kind of obstruct the blood flow through the small vessels leading to severe pain and tissue damage. So, vasoocclusive crisis can actually um affect various organs, tissues including bone, bone joints and the spleen. Then you have the acute chest syndrome as well. And that's actually a life threatening complication, categorized by chest pain, fever, cough, shortness of breath, and it occurs when sickle cells again, block the blood vessels in the lungs leading to lung inflammation and impaired oxygen exchange. Um you have hemolysis. So, sickle cells are pretty much very fragile and prone to breaking apart prematurely, leading to that destruction of your red blood cells, which is hemolysis. And this can result in things like chronic anemia jaundice and increased risk of gallstones. So that's some of the crises that have to be treated as soon as possible. So the way you can manage it is you can manage it acutely or you can manage it long term. So acute management is things like providing pain relief, IV fluids, oxygen, antibiotics and quick transfusion. Long term. On the other hand, you could provide them with penicillin, prophylaxis vaccines, folic acid. So, trying to prevent that um crisis, sickle cell crisis that we have just spoken about from occurring. All right, let's have a look at the clinical importance of enzyme activity. So, enzymes play a critical role in sort of diagnosing um various sort of diseases. So it encompasses very clinical aspects, things like drug targets biomarkers and enzyme deficiencies. So, if we have a look at enzymes in terms of targets for pharmacological interventions, for example, angiotensin converting enzyme um that is pretty much used to treat specific enzyme pathways to modulate that sort of physiological response. For example, in patients like hypertension, an example of that drug could be enalapril, you could have biomarkers. So enzyme activity serves as a biomarker itself. So things like looking at liver function tests. So for instance, utilizing the enzymes like alkaline phosphatase, um gamma glutamyl transferase to evaluate the liver health and identify any sort of liver diseases such as hepatitis cirrhosis. Now changes within these levels can actually indicate whether there is some sort of tissue damage or dysfunction, which will enable us to sort of provide a better diagnosis and monitoring management then that you have enzyme deficiencies and they can have profound clinical consequences as well. Um So things like disruption of your metabolic pathways causing conditions like um phenylketone urea. So PKU. So in PKU, you have low levels of the enzyme phenylalanine hydroxylase. And this leads to the inability to metabolize phenylalanine which again results in the accumulation and causing of that intellectual disabilities and other neurological symptoms if it does get left untreated. So here we can see the molecular techniques. So the way we can actually analyze DNA and RNA A. So I've written like a list below here that you can see and what we can do is we can dissect probably one of the main ones. So let's start off with PCR. So polymerase chain reaction and that is pretty much used to amplify specific regions of the DNA. So in forensic medicine, for example, PCR enables the amplification of the analysis of D DNA from treated samples in things like single cells, hair follicles, sperm. And it helps with the criminal investigation. In essence, by providing that genetic evidence or additionally, it will help with diagnosing inherited diseases. Again, things like thalassemia, sickle cell disease, hemophilia ta sacs by amplifying that specific sequence of that DNA pattern for genetic analysis, which again helps us to determine the disease at an earlier stage and we can intervene if required. Now, in neoplastic disorders, PCR also assists in kind of diagnosing and analyzing things like cancer and detecting their mutation detecting if there's sort of any abnormal gene expression patterns guiding that sort of treatment decision um as a more tailored approach. So alongside of all of that, you have your prenatal and preimplantation diagnosis, which PCR also can work, work on. Um So during pregnancy, which will kind of help us make a productive choice of what sort of abnormalities the unborn child might also have. And an example of a PCR is your multiplex PCR. And this is a technique that amplifies the DNA target simultaneously enhancing the efficiency of the molecular testing. And it enables multiple genes to be recognized. And this way, we can actually see a wider impact on any of the gene mutations if there are any. So the next one is your restriction fragment length polymorphisms. And that is usually combined with gel electrophoresis. So it is a molecular biology technique. It is used clinically to analyze DNA sequences and again detect any genetic variations. So, gel electrophoresis is a method that sort of separates charge molecules such as DNA RNA proteins based on size and charge and in restriction fragment length polymorphisms. The DNA sample is first treated with restriction enzymes which will cut at those particular sites, um known as your restriction sites and that will appear on your gel electro um yeah or paper. Now, in case of diseases such as sickle cell anemia or junctional epidermolysis, bullosa, the single base mutations can actually affect the restriction sites within the genes. And that has a major impact on how it's seen on the gel electrophoresis, um gel or paper. So in sickle cell anemia, you have that single base mutation. remember, and that causes actually a removal of your restriction size within the gene. And in contrast, you have for your J EB, you have a single base mutation which can create new restriction size within the gene. So in this image that you can see here, it's an image of your gel electrophoresis results of your sickle cell anemia. So normally your beta globulin gene should actually break up into two. But patients that have sickle cell anemia because that restriction site is mutated. Um the endonucleases can't actually break it down, which is why you only see a big large sort of thick band on top. And that shows that the mutation is pretty much um dominant in this patient here. So moving on, you have DNA hybridization. So DNA hybridization specifically fluorescence in situ hybridization also referred to as fish is a molecular biology technique and is used to sort of investigating da sequences chromosomal abnormalities in situ, which kind of then means that you have intact cells with tissue still in them. But you can still visualize the DNA once you've kind of probed it with a fluorescent dye, almost in essence. Now, in context of sort of investigating the genes. So fish, which is fluorescence in situ hybridization is actually used to detect things like duplication, amplification of specific genes in a sequence. And again, what you do is literally, you just label it um by the corresponding genes of interest. And again, if they fluoresce, um that gene is present, if they don't fluoresce and they're absent, it might indicate that that gene might have been deleted. Um So we can use the same concept for chromosomal abnormalities. So if it fluoresces quite a bit in different locations, could show or detect sort of trisomy, again, could show translocation or deletion. Um once we visualize it, so it's actually quite a useful tool to kind of detect any sort of trisomy. Um visually. So what we have here is molecular technique analysis of proteins listed. So before it was DNA analysis, but these are the protein analysis. So if we have a look at, for example, Alysa Alysa is a widely use laboratory technique within clinical applications in diagnostic research. Um disease monitoring. And the way it works is that it involves a detection of quantification of specific proteins or even antigens within that biological sample. So it could be blood, it could be serum and the way we detect it is we use monoclonal antibodies that will only bind to that particular antigen um of interest. And once they have detected it, it will fluoresce again. If it fluoresces very similar to fish, it does show a positive result if it doesn't fluoresce, um it shows a negative result. So I've put up a image of the different types of ELISA techniques that are pretty much used. The most common. One is the direct ELISA and it is very similar to how pregnancy testing works and sort of detection of certain antibodies within a individual. So things like detecting hepatitis as an example. So what I've done here also is I've literally just summarized all of the diseases on one slide with their analytes. And what technique you could potentially use to sort of diagnose the patient. So if we move on to personalized medicine, so personalized medicine sort of integrates genetics, environmental and lifestyle factors to sort of tailor the healthcare decisions and treatments to individual patients. Now it encompasses predictions and preventions of diseases. So for example, familial hypercholesterolemia through genetic testing, enabling early intervention strategies. Now also techniques like a multiparametric MRI also allows for more of that precise diagnosis by providing that detailed disease assessments. Um Additionally, personalized interventions such as adjusting warfarin dosages based on the patient's genotype of the CYP two C nine gene, which kind of breaks down the warfarin. Well, actually, nowadays we see that it can optimize the treatment a little bit better. Now patients actively participate in their healthcare by undergoing genomic test. So for example, the uh BVI specific test which guides for medication selection and it minimizes the adverse side effects. So if a patient reacts to this medication or the gene comes up as positive, we don't recommend this particular uh drug for that sort of condition. But if it comes up as negative or they don't have that gene, then we provide them with that medication. And this approach enhances that treatment outcomes by considering each patient uniquely and what their characteristics are and what their needs are. So you have cancer biomarkers, him and cancer biomarkers are pre biological molecules found in the blood, um body fluids. And I it could give you a sign of either a normal or abnormal process depending on the condition and the levels of it. So, like I said, it is an essential indicator for all aspects of cancer management. From early detection and diagnosis to treatment, selection to monitoring treatment response. And these biomarkers include substances, characteristics, things like proteins. It could even be genetic mutations, imaging features. They all provide that valuable information whether a certain cancer is present within the body and by detecting these specific biomarkers associated with the cancer. Um clinicians can actually diagnose the cancer at an earlier stage. Predict the prognosis and kind of select the right level of treatment and monitor the treatment effectively over time. Again, it is a form of personalized medicine. So it is guided by biomarker analysis which provides that sort of more tailored response for the patient. So what we can see here. So if we see a cancer biomarker of, let's say BRCA one, um in a patient's result, it could show up as either maybe breast or ovarian cancer. And for males, if it shows up as psa, so prostate specific antigen could indicate perhaps prostate cancer. So if we have a look at breast cancer, breast cancer is a heterogeneous disease, which is pretty much categorized by that abnormal growth of breast tissue cells. And it's probably the most common type of cancer among women globally. Now, clinically presentation, it varies ranging from painless lumps to thickening in the breast, to um changes in the underarm to changes in breast shape, size, um nipple discharge, skin changes. So it varies and the diagnosis typically involves things like um imaging, ultrasound, um MRI mammographies followed by a biopsy to actually confirm it. So what you can see here is that you can see that there's a varied range of breast cancer subtypes, but there are treatments available for them. Now, for example, the hormone receptor positive breast cancer tamoxifen is probably a most commonly prescribed medication that is metabolized by the enzyme cyp two D six. And when that enzyme metabolizes it, it forms it into an active metabolite called endoxifen. And that active metabolite will actually block the receptor estrogen receptor um pathway in particular. And then you have Herceptin Herceptin is more of a humanized monoclonal antibody. So, anything ending in MB is actually a humanized monoclonal antibody. And it's used for her two positive breast cancer and what it does, it targets her, her two receptors. Um and that's going to potentially inhibit the cancer growth as a whole. Um in that particular area, it is used in early stage um estrogen positive and her two negative breast cancers. Um But for that type of breast cancer, you could also use the oncotype DX test and that analyzes the expression of 16 different types of cancer related genes that will provide us with the information of how the cancer is behaving or the way to the treatment response. So, in a way, this test serves as a prognostic and a predictive test, predicting the likelihood of the benefit of things like chemotherapy radiotherapy or whether you need to go through a different type of management program. So, what I've done here is I've put a few more monoclonal antibodies here for you to have a read. Um But the main ones that we tend to use is Herceptin. But then again, um every type of monoclonal antibody is targeted at um sites and different types of cancers. So for example, Avastin is a, again, a humanized monoclonal antibody and it impacts the vascular endothelial growth and in particular is used in treatments for colorectal cancer. So you've got your therapeutic cancer vaccines and they are a form of immunotherapy nowadays, and they are designed to sort of stimulate the body's um immune system to recognize and attack those sort of cancerous cells. So, unlike the traditional vaccines that sort of prevent the infectious diseases, you've got the therapeutic cancer vaccines, which aim to sort of treat um the existing cancer cells by targeting the tumor specific antigens. And these vaccines can consist of a whole tumor cell. It consists of a tumor antigen or a genetically modified cell that, that just um expresses the tumor antigen. Um But by activating the immune system, the therapeutic cancer vaccines enhances the body's ability to sort of identify and destroy the cancer um itself. So, potentially leading to that tumor regression or prolonged disease stabilization. So, while still under development, it does potentially hold a novel sort of approach to cancer treatment. It hasn't been widely used, but it still is trying to get out there. Um So it offers that potential of personalized and targeted therapy with a fewer side effects in comparison to the traditional treatments like chemotherapy or radiotherapy. But you also have the preventative cancer vaccines. So such as your P I'm sorry, your HPV vaccines, and they aim to reduce the risk of developing specific cancers by inducing that immune response against the cancer causing agent this time. So, for example, the HPV vaccine works by stimulating the production of neutralizing antibodies that will try and block the human papilloma um virus variants, which are pretty much the main cause of cervical cancers, as well as other cancers such as um anal vulvar cancers or oropharyngeal cancers. But by preventing this infection, um the vaccine pretty much helps to significantly lower the risk of developing the HPV associated cancers by providing that sort of long term um protection against these malignancies. So, you, what you've got here is you've got two types of gene therapy that you can see on the image on the side. Now you've got X fever therapy, um gene therapy, which pretty much involves modifying cells outside the body before reintroducing them for therapeutic purposes. And this approach allows the precise genetic modification or enhancement to be made in cells, controlled laboratory conditions before their administration to patients. However, with in vivo therapy, it involves the administration of the therapeutic agent directly into the patient's body where they will then exert their side effects internally. Now, in vivo therapy can actually include treatments such as gene therapy, um all delivered via a viral factor or immunotherapies, um targeting specific cells or molecules within the body. But both in vivo and ex vivo offer a very unique advantage um for various medical um contexts and different diseases. So what you can see on the screen is a X fever gene therapy example. So for example, the car T cell therapy, which is probably the primarily main example used to treat B cell, acute lymphoblastic leukemia in Children as well as young adults. Also, it treats um diffuse large b cell lymphoma um in adults, whereas you've got the next um ex vivo gene therapy and that is pretty much used for severe combined immunodeficiencies mainly to do with adenosine deaminase deficiencies. But it's a very, very rare genetic or autosomal disorder. So, the, the third one that you can see it, all of these are brand names and the third one pretty much treats um beta thalassemia in the same way as the above. Whereas what you can see here is in vivo gene therapy. Now, in vivo gene therapy are examples um such as the splicing therapy for Duchennes muscular dystrophy. And that pretty much targets the DMD gene which pretty much encodes the dystrophin and which is pretty much the largest gene in the human genome. And this gene, um what has happened to it is that is a deletion mutation in a specific exon which leads to a sort of abrupt Mrna splicing and it results in in a sort of nonfunctional dystrophin protein. And what this therapy will do is it will try and restore the normal splicing patterns to allow a more functional protein to be found. Um Whereas the third one that you can see on the side here, it is utilized for the treatment of spinal muscular atrophy, a neuromuscular disorder caused by a mutation of your SM one gene and that leads to a sort of aggressive weakness and paralysis. So, in particular muscle weakness, but when this drug or this gene therapy in particular is being delivered, what it tries to do, it tries to deliver a functional copy of that gene. And this is done through a vector and is trying to restore the functions of those proteins um to help with the motor functions. And lastly, you've got your drug repurposing, also known as rep profiling. And it involves identifying that new therapeutic uses for existing drugs um where originally they were developed for different indications. And this approach has several advantages. So in including reduced development of time cost, um and sort of trying to compare it traditional drug discovery methods. But also at the same time, we're trying to look at the safety profiles and the pharma kinetics of the already drug approved to try and see if there's a faster way to translate that drug from bench to bedside. So it provides that sort of novel treatment for various diseases. So for example, with aspirin, it used to be or initially was a analgesic, sometimes it's still used as one. But nowadays, it could also be used as a antiplatelet aggregation. But what they have recently been trying to do is they're trying to see whether Aspirin has oncological factors where it can help with cancer treatment on the side as well. Another one is SFIL, which was initially used as a hypertensive drug to treat um angina. But what they've noticed was that they had um unexpected side effects so it sort of caused vasodilation and um within the penile erection. But nowadays, it could also be used for idiopathic forms of pulmonary arterial hypertension. So that was pretty much it for my whistle stop tour of genetics and disease. Um The floor is pretty much open to any questions if you guys have any questions, if not any questions, I would just like to say thank you so much Eddie for hosting the session today. It was very enjoyable. Very infor. Oh, we have one question holder. Hold on. Um You can unmute, you can unmute.