Haemogloinopathies

Question 1

What is the structure of HbA?

Answer 1

2 alpha 2 beta

Question 2

What is the structure of HbA(2)

Answer 2

2 alpha 2 delta

Question 3

What is the structure of HbF?

Answer 3

2 alpha 2 gamma

Question 4

Where is the alpha globin-like gene located?

Answer 4

Chromosome 16

Question 5

Where is the beta globin like gene located?

Answer 5

Chromosome 11

Question 6

How are haemoglobinopathies generally inherited?

Answer 6

AR

Question 7

What is a thalassaemia?

Answer 7

Reduced globin chain synthesis leading to inadequate Hb production

Question 8

Which type of anaemia is seen in the thalassaemias?

Answer 8

Microcytic hypochromic

Question 9

What is the mildest form of alpha thalassaemia called?

Answer 9

Alpha thal trait

Question 10

What is HbH disease?

Answer 10

Only 1 functioning copy of the alpha gene

Question 11

What is Hb Bart Hydrops fetalis?

Answer 11

No functional copies of the alpha gene

Question 12

How does alpha thal trait present?

Answer 12

Asymptomatic

May have mild anaemia

Question 13

What is the most severe form of alpha thalassaemia?

Answer 13

Hb Barts Hydrops fetalis

Question 14

How does HbH disease present?

Answer 14

Splenomegaly
Jaundice
Severe anaemia 
Gall stones
Growth retardation
Iron overload

Question 15

What happens to excess beta chains in HbH disease?

Answer 15

Form tetramers

Question 16

How is HbH disease treated?

Answer 16

Transfusions

Maybe splenectomy

Question 17

Where is HbH disease most common?

Answer 17

SE Asia

Middle east

Question 18

Which kinds of Hb are found in Hb Barts Hydrops Foetalis?

Answer 18

Hb Barts

HbH

Question 19

What is Hb Barts?

Answer 19

4 gamma chains

Question 20

What is HbH

Answer 20

4 beta chains

Question 21

How does Hb Barts Hydrops Foetalis present?

Answer 21

Severe anaemia
Cardiac failure
Growth retardation
Hepatosplenomegaly

Question 22

What type of Hb is affected in beta thalassaemia?

Answer 22

HbA

Question 23

What is the mildest form of beta thalassaemia?

Answer 23

Beta thal trait

Question 24

How does beta thal trait normally present?

Answer 24

Asymptomatic

Mild anaemia

Question 25

What does Hb electrophoresis show in beta thal trait?

Answer 25

Increased HbA2 and HbF

Question 26

How does beta thal intermedia present?

Answer 26

Symptomatic anaemia | May be splenomegaly and iron overload

Question 27

How is beta thal intermedia treated?

Answer 27

Blood transfusions

Question 28

When does beta thal major present?

Answer 28

6-24 months

Question 29

How does beta thal major present?

Answer 29

Failure to thrive | Recurrent infection

Question 30

What does extramedullary haematopoiesis cause in beta thal major?

Answer 30

Splenomegaly Skeletal change Organ damage

Question 31

What does Hb electrophoresis show in beta thal major?

Answer 31

Mostly HbF

Question 32

What should the target Hb be in beta thal major?

Answer 32

95-105 g/l

Question 33

How is beta thal major managed?

Answer 33

Transfusions regularly | Bone marrow transplant in kids

Question 34

What is the main cause of death in beta thal major?

Answer 34

Iron overload

Question 35

What cardiac complications may iron overload cause?

Answer 35

Arrhythmia | Cardiomyopathy

Question 36

What hepatic complications may iron overload cause?

Answer 36

Cirrhosis | Hepatocellular cancer

Question 37

What endocrine complications may iron overload cause?

Answer 37

Diabetes | Osteoporosis

Question 38

How is iron overload treated?

Answer 38

Iron chelating agents

Question 39

Give examples of iron chelating agents?

Answer 39

Desferrioxamine Deferiprone Deferasirox

Question 40

How is desferrioxamine given?

Answer 40

IV | s/c

Question 41

What do you need to be wary of in giving high dose desferrioxamine?

Answer 41

Ocular and ototoxicity

Question 42

How is deferiprone given?

Answer 42

Oral

Question 43

What is the main risk with deferiprone?

Answer 43

Agranulocytosis

Question 44

What are the main side effects of deferiprone?

Answer 44

Arthralgia | GI upset

Question 45

Where is the mutation in sickling disorders?

Answer 45

codon 6 of beta-globin gene

Question 46

What is the mutation in sickling disorders?

Answer 46

Glutamine to valine

Question 47

What is HbS?

Answer 47

2 alpha 2 beta (S)

Question 48

Describe the pathogenesis of sickling disorders

Answer 48

HbS polymerises when exposed to low O2 and distorts the red cell membrane

Question 49

What causes sickle crisis?

Answer 49

Distorted shape leads to impaired blood flow and prothrombotic cell adhesion to the outside The cells get stuck in smaller arteries and cause ischaemia

Question 50

What Hb is found in sickle trait?

Answer 50

HbAS

Question 51

How does sickle trait present?

Answer 51

Asymptomatic | May have clinical features in severe hypoxia

Question 52

What does blood film show in sickle trait?

Answer 52

No abnormality

Question 53

What does electrophoresis show in sickle trait?

Answer 53

HbA

Question 54

What Hb type is seen in sickle cell anaemia?

Answer 54

HbSS

Question 55

How does sickle crisis present?

Answer 55

Severe pain Erythema Inflammation All local to site of crisis

Question 56

Describe spleen activity in sickle cell anaemia?

Answer 56

Hyposplenic due to repeated infarcts

Question 57

How is acute sickle crisis treated?

Answer 57

IV fluids and morphine

Question 58

How is sickle cell anaemia treated?

Answer 58

Hydroxycarbamide | Splenectomy

Question 59

In cases of previous stroke what is considered in sickle cell anaemia?

Answer 59

Blood transfusion

Question 60

What does hydroxycarbamide do?

Answer 60

Induces HbF production

Question 61

What is given in cases of splenectomy?

Answer 61

Prophylactic life long penicillin Folic acid Vaccination - pneumococcus, meningococcus and haemophilus

Question 62

How may sickle cell anaemia be treated in kids?

Answer 62

Bone marrow transplant before any real damage done?

Question 63

How does sickle cell anaemia affect growth and development?

Answer 63

Short as children but regain height by adulthood | Delayed sexual maturation requiring hormone therapy

Question 64

How may sickle cell anaemia affect bone growth?

Answer 64

Chronic infarcts cause AVN of hips and shoulders | May be shortened bones in hands and feet

Question 65

What three organisms typically cause osteomyelitis in sickle cell anaemia?

Answer 65

S aureus Strep pneumo Salmonella