V.C - M - Haematopoiesis (Foetal/Adult) in vertebrae - Marrow, Cell lineages, Inherited disorders, Hypo/hyperplasia, Thalassemia

Question 1

Define haematopoeisis?

Answer 1

This is the process by which all the blood cells and blood cellular components are formed

Question 2

When does haematopoeisis begin? What are the types of mature blood cells?

Answer 2

Haematopoeisis begins from as early as 3 weeks gestation in the yolk sac and continues throughout life in order to reproduce and replenish the blood supply Mature blood cells Erythrocytes (red blood cells) Thrombocytes (platelets) Leukocytes (white blood cells)

Question 3

The earliest place that blood cell formation is seen in the embryo is in the yolk sac at around three weeks gestation. When does haematopoeisis in the yolk sac continue until?

Answer 3

The yolk sac continues producing blood cells up until the 10th week of gestation

Question 4

How does blood first appear from the yolk sac?

Answer 4

Around week 3 of development, blood islands form in the yolk sac arising from mesodermal cells that form hemangioblasts which are precursors to blood cell formation

Question 5

Three waves of cells then arise from the yolk sac one after the other. What is this process known as?

Answer 5

The process of the three waves of cells arising from the yolk sac is known as extraembryonic haematopoeisis

Question 6

What is the first wave arising from the yolk sac in extraembryonic haematopoeisis?

Answer 6

The first wave of cells serve the immediate needs of the growing embryo and are mainly large nucleated erythrocytes

Question 7

The first wave in extra-embryonic haematopoisis is to serve the immediate needs of the embryo and binucleated erythrocytes are formed in the yolk sac What are the second wave of cells formed in the yolk sac?

Answer 7

The second wave of cells formed in the yolk sac rapidly follows the first one and consists of erythromyeloid progenitors and lymphoid progenitors that seed the foetal liver

Question 8

The second wave of cells from the yolk sac rapidly follow the first wave and consist of erythromyeloid progenitors and lymphoid progenitors that seed the liver What is the third wave of cells produced in the yolk sac during extra-embryonic haematopoeiss?

Answer 8

The third wave of cells includes self-renewing haematopoieitc cells and it gives rise to the permanent adult haematopoietic system

Question 9

What is the debate in the literature regarding the third wave of cells from the yolk sac?

Answer 9

There is debate in the literature about whether the haemapoietic stem cells actually arises from the aorto-gonad-mesoneprhos region or from precursor cells in the yolk sac If the HSC actually arise from the aorto-gonad-mesonephros region, then this would support the theory that the cells actually arise in vitro (locally)

Question 10

Lets talk about the aorto-gonad-mesonephos region What is this region and what definitive cells arise from here?

Answer 10

The aorto-gonad-mesonephros region is an area of mesoderm surrounding the aorta which is where definitive haematopoeitic stem cells arise from

Question 11

After the HSC arise in the aorto-gonad-mesonephors region, where do they go?

Answer 11

These cells will then go on to colonise the liver in order for it to become the major haematopoietic organ of the embryo/foetus before colonising the bone marrow near birth

Question 12

As said the liver is colonised by haematopoeitc stem cells that have migrated to the liver via the blood stream from the mesoderm around the aorta What period is the liver the major site of haematopoeisis in the embryo? What happens to the livers blood forming function after this? Which other organ do the HSC colonise to some extent?

Answer 12

The liver is the major site of haematopoesis from the second to seventh month of gestation After this the liver loses its blood forming function as the HSC migrate to the bone marrow The HSC also colonize the spleen to some extent after being produced in the aorta-gona-mesonephros region

Question 13

When does the bone marrow become colonized by stem cells? What part of the bone does the HSC from the liver colonize?

Answer 13

The bone marrow becomes colonized by stem cells from the liver at 7 months gestation As the bone develops it forms cavities, it is these cavities that the cells colonize

Question 14

The red bone marrow in and adult skeleton acts as a lifelong reserve of HSC and is the site which haematopoiesis takes place. Which organs still carry some residual haematopoietic activity after birth when needed? Where is the main sites of haematopoiesis in children and adults?

Answer 14

The spleen and liver still carry some residual haematopoeitc activity after birth when needed Main sites of haematopoesis in children - long bones Main sites of haematopoeiss in adults - no longer in long bones but mainly in the pelvis, sternum, ribs, cranium, vertebrae and proximal aspect of long bones (the axial skeleton mainly)

Question 15

What is bone marrow and where is it found? What percentage of the body weight does it account for?

Answer 15

Bone marrow is the soft, spongy gelatinous tissue found in the hollow cavities of flat and long bones It accounts for 5% of the body weight

Question 16

Bone marrow is made of hematopoietic tissue islands and adipose cells that are surrounded by vascular sinusoids. What part of the bone are these haematopoietic tissue islands and aipose cells interspersed within? What are the two types of stem cells that can be found in the bone marrow?

Answer 16

The bone marrow is interspersed within the network of trabeculae within the cancellous bone The two types of stem cells found in bone marrow or haematopoeitc stem cells (blood) and mesenchymal stem cells (cartilage and bone)

Question 17

The scaffolding of the bone marrow is comprised of components of the extra cellular matrix. It is this scaffolding which provides stiffness to the bone marrow making it the ideal environment for hematopoietic stem cells to differentiate. What is the difference in blood supply to the bone marrow in flat and long bones?

Answer 17

Flat bones, bone marrow blood supply - numerous blood vessels entering via large and small canals Long bones, bone marrow blood supply - one or more arteries passing through the cortical bone network to enter the bone marrow

Question 18

Two types of bone marrow are red and yellow bone marrow Which replaces the other with age? Which is mainly made up of adipose cells? Which is the haematopoietic portion of bone marrow? Which can be converted to the other in times of stress?

Answer 18

Red marrow is mainly made up of haematopoietic stem cells and yellow marrow is mainly made up of adipose tissue The red marrow is replaced with yellow marrow in aging process In times of stress, the yellow marrow can be converted into the red marrow

Question 19

What is the difference between where red and yellow marrow is found in adults? What is the difference in function of red and yellow marrow?

Answer 19

Red bone marrow is found in flat and short bones, articular ends of long bones, bodies of vertebrae, cranium, sternum and ribs Yellow marrow is found in the shafts of long bones * Red marrow serves to produce and remove blood cells from circulation * The function of yellow marrow is uncertain and it is thought that it may provide surface and nutritional support for red marrow

Question 20

Bone marrow is a complex tissue, and as we have already seen it contains hematopoietic, mesenchymal and endothelial cells. It is also organized into distinct niches in order to regulate haematopoiesis. What are the two niches organised within the bone marrow?

Answer 20

The two niches organised within the bone marrow are the endosteal and perivascular niche

Question 21

There are two niches within the bone marrow which are the perivascular and endosteal niches and they both act differently to influence HSC function. Where is the endosteal and perviascular niches located?

Answer 21

The endosteal niche is located at the bone-bone marrow interface The perivascular niche is located within the bone marrow

Question 22

What haematopoietic stem cells are located in the endosteal and perivascular niche?

Answer 22

The long term haematopoietic stem cells are located within the endosteal niche of the bone at the bone-bone marrow interface The short term haematopoietic stem cells are located within the perivascular niche near the sinusoid and perivascular cells within the bone marrow

Question 23

Which niche supports HSC proliferation and maturation?

Answer 23

The perivascular iche supports HSC proliferation and maturation

Question 24

Another structure located at the niches within the bone is the haemosphere. What has there function been found to be? When are haemospheres formed?

Answer 24

The function of the haemosphere has been found to recruit and maintain HSCs The haemasopheres are formed whenever bone is remodelled around a blood vessel and it is maintained by singaling through the vascular endothelial growth factor receptor 2 (VEGFR 2) located on endothelial cells

Question 25

There is a hierarchal system for the process in which HSC are driven down specific cell pathways to form specific cell types Production of blood cells controlled by growth factors and hormones. Produced locally in bone marrow or are systemic. How do the LT-HSC give rise to the myeloid and lymphoid lineages?

Answer 25

LT-HSC are at the top of the hierarchal system and are capable of self-renewal and multilineage differentiation They will differentiate to form ST-HSC which are capable of multilineage differentiation which differentiate to form multipotent progenitor cells - these descend to either common myeloid progenitors or lymphoid multipotent progenitor cells

Question 26

The CMP differentiates to form GMP and MEP cells What do these acronyms stand for? What do GMP and MEP cells produce?

Answer 26

CMP - common myeloid progenitor - forms GMP and MEP GMP - graanulocyte macrophage progenitor - forms granulocytes and macrophages MEP - megakaryocyte-erythrocyte progenitor - forms platelets and red blood cells (erythrocytes)

Question 27

What do lymphoid multipotent progenitor cells give rise to?

Answer 27

LMPP cells give rise to Common lymphoid progenitors (CLP) which form lymphoid lineages B cells T cellls Natural killer cells (and dendritic cells)

Question 28

What is the most abundant type of blood cell? What is its function? What are they derived from in embryos and adults?

Answer 28

The most adunant type of blood cell in the body is the red blood cell (erythrocyte) It functions to carry oxygen to all of the body tissues In embryos there is a primitive and definitive lineage of eryhtrocytes In adults, all red blood cells are produced from HSCs found in the red bone marrow

Question 29

What is the difference between the primitive and definitive lineages in the embryo?

Answer 29

The first lineage of primitive erythrocytes develops early in gestation and produced nucleated red blood cells The second lineage of definitive erythrocytes is produced in the foetal liver and this continues throughout pre-natal life (by month 7, bone takes over as major organ responsible for haematopoeisis)

Question 30

What are platelets derived from? When can platelet production be increased?

Answer 30

Platelets are derived form very large cells known as megakarycoytes which remain in the bone marrow Platelet production can be increased in times of excess

Question 31

The megakaryocytes produced platelets by undergoing multiple duplications of its nuclear material but never undergoes nuclear or cellular division. The platelets are formed from the extensions of the margins of the shell that have been fragmented off. After the cell has produced thousands of platlets the cell will undergo cell death by apoptosis. What are the extensions of the megakaryocytes that allow the platelets to enter the sinusoids and later the circulation known as?

Answer 31

These extensions from which platelets extend from the megakaryocyte are known as proplatelets

Question 32

Macrophages are large cells that reside all over the body but particularly in loose connective tissue . When do they arise from and after how many days?

Answer 32

Macrophages arise from monocytes which which remain in circulation for 1-2 days before entering the tissues and becoming macophages

Question 33

What is the main function of macrophages?

Answer 33

The main functions of macrophages are tissue regulation, immune regulation and fighting pathogens

Question 34

The granulocytes are divided into three groups - neutrophils, eosinophils and basophils What is the function of ll three cells?

Answer 34

Neutrophils are important as a 1st line in defence and phagocytose bacteria Eosinophils reside mainly in the spleen, lymph and GI tract and are important for fighting parasitic infections and hypersensitivity Basophils contain histamine & heparin which are released in the presence of an allergen

Question 35

Where are B and T cells produced and where do they mature?

Answer 35

B cells - produced in bone marrow - mature in bone marrow T cells - produced in bone marrow - mature in thymus

Question 36

Part of the adaptive immune system. Central in determining type and intensity of immune response. Essential part of humoral component of immune system. Which statement applies to B and which to T cells?

Answer 36

T cells are part of the adaptive immune system and are central in determining type and intensity of immune response - can give rise to Killer T cells and T helper cells B cells are an essential part of humoral component of immune system

Question 37

What cells do B cells give rise to? What do T cell deficiencies include? (name the two big hitters)

Answer 37

B cells give rise to plasma cells which produce antibodies to fight infection and disease Tcell deficiencies can lead to HIV and AIDS

Question 38

Bone marrow failure syndromes are a group of rare genetic blood disorders in which there is usually some form of aplastic anaemia which is the failure of the bone marrow to produce blood. What is amegakaryocytic thrombocytopenia? What is the inheritance?

Answer 38

This is a rare inherited (congenital) or acquired disorder resulting in a reduction or absence of megakaryocytes in the bone marrow causing a severe platelet deficiency Amegakaryocytic thrombocytopenia is inherited in an autosomal recessive fashion

Question 39

What is amegakaryocytic thrombocytopenia caused by?

Answer 39

Amegakarycotic thrombocytopenia is caused by a mutation in the MPL gene which codes for the thrombopoeitin receptor (c-MPL) Loss of the TPO/c-MPL pathway with consequent increase in thrombopoeitin is thought to be a unifying factor in amegakaryocytic thrombocytopenia

Question 40

What are the symptoms of amegakaryocytic thrombocytopenia? (would be symptoms of a primary haemostatic disorder remember)

Answer 40

Symptoms - \* Easy bruising \* Prolonged bleeding from minor cuts \* Bleeding from mucous membranes - bleeding in the mouth and gums and nose (epistaxis) \* Bleeding into skin causing pinpoint red spots - petechiae

Question 41

What is the treatment of megeakaryocytic thrombocytopenia?

Answer 41

Treat with Immunosuppressant therapy eg rituximab, danazol, azathioprine or Bone marrow transplant

Question 42

What is Diamond Blackfan Anaemia? What is it also known as? What is its inheritance?

Answer 42

Diamond-blackfan anaemia - aka congenital red cell aplasia This is a rare ribosomopathy - arises due to mutation in the genes which provide instructions to make several different ribosomal proteins Dimond Blackfan Anaemia is inherited in an autosomal dominant fashion

Question 43

What cells are there a decrease in, in the bone and what does this cause in the blood in Diamond Blackfan Anaemia?

Answer 43

There is a decrease in erythroid precursors in the bone marrow leading to a normochromic but macrocytic anaemia in the blood (haemoglobin within RBCs is within the normal range but there are far fewer red blood cells so the ones produced are immature and large than they should be)

Question 44

In Diamond Blackfan Anaemia, Heterozygous mutations identified in 11 genes = cause haploinsufficiency in the ribosomal proteins. What is haploinsufficinecy? Mutation in which gene is seen in70% of cases in this condition?

Answer 44

Haploinsufficiency - causes a pathological phenotype due to a diploid organsim (the ribosome) only being left with one functional copy of a gene A mutation in the GATA1, which is an erythroid differentiation gene is seen in 70% of cases of diamond-blackfan anaemia

Question 45

What are the symptoms in Diamond Blackfan syndrome?

Answer 45

Children develop with an unusually small head (microcephaly), wide set eyes and droopy eyelids (ptosis), a small lower jaw (micrognathia), Individuals may also have a cleft palate with or without a cleft lip and shoulder blades that are smaller and higher than usual As well as absent thumbs

Question 46

What is the treatment of diamond blackfan anaemia?

Answer 46

Treatment includes steroids + blood transfusions Bone marrow transplant may be option for cure

Question 47

Dyskeratosis congenita is a rare progressive congenital disorder than can have a highly variable phenotype and affect many parts of the body What is it caused by?

Answer 47

Dyskeratosis congenita aises due to a mutation in the telomere repair genes leading to short telomeres that do not function correctly

Question 48

What are the symptoms in dyskeratosis congenita?

Answer 48

There are three usual characterisitc features of dyskeratosis congenita - \* abnormally shaped nails (nail dystrophy), \* abnormal skin pigmentaiton - usually on the face, neck and chest, \* and white patches on the oral ucosa (leukoplakia) A major consequence of this progressive disease is that individuals also develop bone marrow failure (aplastic anaemia)

Question 49

What is the treatment of dykeratosis congenita?

Answer 49

Treeatment includes androgen therapy and stem cell transplantation

Question 50

What is fanconi anaemia? What does it arise due to? What is there a high risk of transformation to?

Answer 50

Fanconi's anaemia is a rare inherited disorder that can cause aplastic anaemia It arises due to gene mutations causing the inability to repair inter-strand cross links that have damaged DNA With Fanconi's anaemia, the individual is at an increased risk of developing acute myeloid leukaemia

Question 51

. A large number of patients present towards the end of the first decade of life with uni- or bi- lineage cytopenias (reduction in the number of mature blood cells in the body) in fanconi's anaemia What are the symptoms? What is the treatment?

Answer 51

Dermatitis Genitourinary - cryptoorchidism (failure of descent of the testes) Gastrointestinal Cardiac and neurological abnormalities the treatment is a stem cell transplant

Question 52

What is severe congenital neutropenia characterised by? What is it also known as?

Answer 52

Severe congenital neutropenia is characterised by a profound lack of neutrophils in the blood ( 9 /litre) causing affected individuals to be very prone to infections Severe congenital neutropenia aka Kostmann syndrome

Question 53

What do greater than 40% of patients with SCN progress to?

Answer 53

\>40% of patients progress to myelodysplsia- cancer manifesting as marrow failure - and acute leukaemia USually there is the acquisition of a G-CSF secondary mutation (granulocyte - colony stimulating factor)

Question 54

What mutation most commonly causes severe congenital neutropenia?

Answer 54

In most cases, there is a mutation in the neutrophil elastase gene - ELANE (formerly ELA-2 gene) causing autosomal dominant cases - mutations in this gene lead to accumulation of a non-functional protein which in turn triggers an unfolded protein leading to arrest in neutropphil maturation

Question 55

Heterozygous mutations in neutrophil elastase gene = leads accumulation of non-functional protein which in turn triggers an unfolded protein response. What is the mutated gene that leads to defects in cell death causing SCN known as? This usually causes an autoosomal inheritance of the disease

Answer 55

This would be the HAX1 gene - causes defects in cell death

Question 56

What are the symptoms and treatment of severe congenital neutropenia?

Answer 56

Sympotms - Infections Fevers Inflammation of the lungs Inflammation of the gums Ear infections Treatment is through granuocyte colony-stimulating factor (G-CSD)

Question 57

Schwachman Diamond Syndrome is a rare autosomal recessive multi-systemic inherited disorder What is usually the presentation in blood and what can it progress to? What parts of the body does it particularly affect?

Answer 57

Most individuals usually present with a neutropenia that can progress to a pancytopenia The disease may progress to acute myeloid leukaemia in a significant number of patients Uusally the syndrome affects the bone marrow, pancreas and skeletal syndrome

Question 58

What is thought to the be the cause of Schwachman Diamond Syndrome?

Answer 58

In 90% of cases Schwachman Diamond Syndrome arises due to a a bi-alleic mutation in the SBDS gene which plays an important role in the maturation of the 60S ribosomal subunit and therefore important in ribosome biogenesis

Question 59

As said the symptoms of SDS affect: Bone marrow Pancreas Skeletal system What is the treatment of the disease?

Answer 59

\* Correction of haematological abnormalities when possible \* Pancreatic enzyme supplementation \* Prevention of orthopaedic deformities

Question 60

We will now Discuss The Aetiology and Effects of Hypoplasia and Hyperplasia of the Bone Marrow of the Vertebral Column What is hypoplasia? What does bone marrow hypoplasia result in?

Answer 60

Hypoplasia is the underdevelopment or incomplete development of an organ or tissue Bone marrow hypoplasia results in a decrease in all three cell lineages and can be idiopathic or secondary from other causes

Question 61

What are factors that can injure the bone marrow? What are the symptoms of bone marrow hypoplasia? What is the treatment?

Answer 61

Factors that can injure bone marrow: Drugs, Radiation and chemo Tx Exposue to toxic chemicals Autoimmune disorders, Pregnancy, Viral infecitons Symptoms - Fatigue High risk of infection Uncontrolled bleeding Treatment- Medications Blood transfusion Stem cell transplant

Question 62

Define hyperplasia? What can happen in bone marrow hyperplasia?

Answer 62

This is an increase in the number of cells in a tissue or an organ Bone marrow hyperplasia can involve one or all three cell lineages and has the potential to become malignant

Question 63

First we will talk about benign hyperplasia affecting once cell line include \* Erythroid hyperplsia \* Myeloid hyperplasia \* Megakaryocyte hyperplasia Describe how each of these occurs?

Answer 63

\* Eryhtoid hyperplasia - occurs in haemolytic anaemia (tries to produce more red cells because red cells are being destroyed), high altitude (need more oxygen) or hypoxia (need more oxygen) \* Myeloid hyperplasia - infections, compensatory hyperplasia after cell destruction \* Megakaryocyte hyperplasia - due to immune thrombocytopenia

Question 64

Lets now talk about malignant causes affecting one cell line \* Erythroid hyperplasia \* Myeloid hyperplasia \* Megakaryocyte hyperplsia Describe how each of these occurs?

Answer 64

Myeproliferative disorders include (MPDs)- polycythaemia ruba vera, essential thrombocytosis, idiopathic myelofibrosis and chronic myeloid leukaemia \* Erythroid hyperplasia- polycythemia vera, dysregulated erythropoietin production by various neoplasms. \* Myeloid hyperplasia - myeloid neoplasms \* Megakaryocytic hyperplasia - Essential thrombocytosis and acute megakaryoblastic leukaemia MPDs are considered when there is no reactive explanation

Question 65

What are the symptoms of bone marrow hyperplasia? What is the treatment?

Answer 65

Back pain Fatigue Bruising and bleeding Infections Treatment Blood transfusions Stem-cell transfusions

Question 66

Lets discuss the effects of thalassemia on the vertebral column What is thalassemia?

Answer 66

This is where there is reduced or absent globin chain synthesis resulting in impaired haemoglobin production

Question 67

In Thalassemia Genetic and acquired risk factors lead to osteoporosis, pathologic fractures of the spine, and back pain. What does the increased iron overload due to thalassemia treatment lead to? (keep this relevant to vertebral column)

Answer 67

The increased iron overload due to thalassemia treatment leads can lead to osteoporsis of the vertebral spine maing fractures more likely, as well as IV disc degeneration

Question 68

Thalassemia cause ineffective erythropoiesis and therefore drives extramedullary tissue formation ie in the vertebral column What can this result in?

Answer 68

This can result in overt scoliosis a well as spinal cord compression

Question 69

What is the management of the adverse effects on the vertebral column due to thalassemia?

Answer 69

Biphosphonates - prevent bone resoprtion Transfusion therapy to stop extramedullary haematopoeisis Laminectomy if spinal cord compresison Radiotherapy Foetal haemoglobin

Question 70

QUIZ TIME WHAT IS HAEMATOPOIESIS? 1. A naturally regenerative process that forms all of the bodies blood cells 2. A naturally regenerative process that forms some of the bodies blood cells 3. A naturally regenerative process that forms only white blood cells 4. A non regenerative process that forms all of the bodies blood cells.

Answer 70

1. Haematopoiesis is a naturally regenerative process that forms all the bodies blood cells

Question 71

WHERE DOES HAEMATOPOIESIS OCCUR IN THE ADULT? 1. Red bone marrow of the ribs, sternum, vertebrae. 2. Yellow bone marrow of the cranium, vertebrae and sternum. 3. Red bone marrow of the pelvis, cranium, vertebrae, sternum, ribs and proximal long bones. 4. Yellow bone marrow of pelvis, proximal long bones and vertebrae.

Answer 71

3. Haematopoeisis occurs in the red marrow of the pelvis, carnium, vertebrae, sternum, ribs and proximal long bones in the adult

Question 72

WHERE DOES HAEMATOPOIESIS OCCUR IN THE FOETUS? 1. Yolk sac, liver, bone marrow 2. Yolk sac, aortic-gonad- mesonephros region, spleen, bone marrow 3. Yolk sac, aortic-gonad-mesonephros region, spleen, liver, bone marrow 4. Yolk sac, aortic-gonad-mesonephros region, liver, bone marrow THE YELLOW BONE MARROW IS THE SITE OF HAEMATOPOIESIS. True OR False

Answer 72

3. Haematopoiesis occurs in the yolk sac, aortic-gonad-mesonephros region, spleen, liver and bone marrow in the foetus False - red marrow is the site of haematopoiesis

Question 73

WHICH OF THE FOLLOWING CELLS UNERGOES SELF RENEWAL? 1. Multipotent progenitors 2. Short term hematopoietic stem cells 3. Long term hematopoietic stem cells 4. Common myeloid progenitor HOW IS AMEGAKARYOCYTIC THROMBOCYTOPENIA CAUSED?

Answer 73

Long term haematopoietic stem cells undergo self renewal Amegakaryocytic thrombocytopenia is caused by a mutation in the gene that codes for the thombopotein receptor (c-MPL) - therefore there is the loss of signalling in the TPO/c-MPL pathway

Question 74

HYPOPLASIA IS THE OVERDEVLOPMENT OF AN ORGAN OR TISSUE. \* True \* False WHICH CELL LINEGAGE CAN HYPERPLASIA AFFECT? 1. Erythrocytes 2. Megakaryocytes 3. Granulocytes 4. All of the above

Answer 74

Hypoplasia is the underdevelopment of an organ or tissue 4. Hyperplasia can affect erythrocytes, megakaryocytes and granulocytes

Question 75

WHAT AFFECT DOES THALASSAEMIA HAVE ON HAEMOGLOBIN? 1. Overproduction of haemoglobin 2. No effect 3. Produce very little or no haemoglobin 4. Destroys haemoglobin ALL OF THE INHERITED BONE MARROW FAILURE SYNDROMES CAN BE TREATED BY STEM CELL TRANSPLANTS. \* TRUE OR FALSE

Answer 75

Thalassemia caused the production of very little or no haemoglobin False - the inherited bone marrow failure syndromes cannot all be treated by stem cell transplants

Question 76

WHICH OF THESE IS AFFECTED BY SHWACHMAN DIAMOND SYNDROME? 1. Bone marrow 2. Pancreas 3. Skeletal system 4. All of the above BONE MARROW HYPERPLASIA CAN BECOME CANCEROUS. \* True \* False

Answer 76

4. Scwachman diamond syndrome caused by a bi-alleic mutation in the SBDS gene which has a role in the maturation of the 60S ribosomal subunit and therefore in ribosomal biogenesis affects the bone marrow, pancreas and spleen True - bone marrow hyperplasia can become cancerous