Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

J Haem > Haemoglobinopathies > Flashcards

Haemoglobinopathies Flashcards

1
Q

what are the haemoglobinopathies (2)

A

thalassaemia

sickle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

where are haemoglobinopathies common (not UK)

A

SE asia

Africa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the primary problem in thalassaemia

A

abnormal globin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what type of anaemia does thalassaemia cause

A

microcytic anaemia (same as iron deficiency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

in alpha thalassaemia, which chromosome is the mutation on

how many alpha genes are on this chromosome
hence how many alpha genes do we have in total (x2 for each parent)

clinical significance of this

A

16

2 alpha genes on each chromosome 16
so 4 alpha genes altogether

means you need 2 copies of gene to have complete failure of alpha chain synthesis (if one copy = just reduced synthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what type of haemoglobin (HbF, HbA HbA2) does alpha thlassaemia affect

A

all! bc they all contain alpha subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how many of the 4 alpha genes is someone missing if they have alpha thalassaemia trait

A

one or 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

treatment of alpha thalassaemia trait

A

nothing - theyre fine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how many of the 4 alpha genes is someone missing if they have HbH disease (type of alpha thalassaemia)

A

3 missing = only 1 of the 4 remains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens in HbH disease (type of alpha thalassaemia)

A

all the unbound beta chains form a HbH haemoglobin (not functional)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how many of the 4 alpha genes is someone missing if they have Hb barts hydrops (hydrops fetalis)

what does this mean

A

all 4 missing = no alpha genes

cant make any HbA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

most severe form of alpha thalassaemia

prognosis

A

Hb bart hydrops (hydrops fetalis)

most die in utero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

management of HbH disease (type of alpha thalassaemia)

A

transfusion

splenectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

presentation of HbH disease (type of alpha thalassaemia)

why does this happen

A

splenomegaly and jaundice

from hemolysis - breakdown of RBCs (HbH) bc theyre useless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

in beta thalassaemia, which chromosome is the mutation on

how many beta genes are on this chromosome
hence how many beta genes do we have in total (x2 for each parent)

A

chromosome 11

1 beta gene on each chromosome 11
so 2 beta genes altogether

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what type of haemoglobin (HbF, HbA HbA2) does beta thalassemia affect

what does this mean

A

only affects HbA
doesn’t affect HbA2 or HbF

can compensate for loss of HbA by increasing HbF/HbA2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what kind of chains are in HbA2

A

4 alpha chains

18
Q

what are the 3 classifications of beta thalassaemia

A

beta thalasaemia trait
beta thalasaemia intermedia
beta thalasaemia major

19
Q

investigations for beta thalassaemia

what are the results

A

gel electrophoresis/HPLC (high performance liquid chromatography)
will see raised HbA2

20
Q

management of beta thalasaemia trait

A

nothing

21
Q

management of beta thalasaemia intermedia

A

occasional transfusions

22
Q

management of beta thalasaemia major

A

life long RBC transfusion with iron chelating drugs (desferrioxamine) to prevent iron overload

OR

bone marrow transplant - curative but rarely done

23
Q

presentation of beta thalasaemia major

at what age

A

age 6-24 months, whenever the HbF runs out

pallor
failure to thrive
extramedullary haemotopoiesis - splenomegaly, bony deformities

24
Q

what xray appearance of beta thalasaemia major

A

cortical thinning

‘hair on end’ bone appearance

25
Q

how many of the beta genes is someone missing if they have beta thalasaemia major

what does this mean

A

them all

no beta chain production = no HbA

26
Q

cortical thinning

‘hair on end’ bone appearance

A

extramedullary haematopoiesis in beta thalasaemia major

27
Q

blood film cells in beta thalasaemia major

A

target cells
nucleated RBCs
alpha chain precipitates (bc loads are unbound)

28
Q

what type of haemoblogin in sickle cell trait

A

HbAS

half HbA half HbS

29
Q

presentation of sickle cell trait

A

asymptomatic unless sickle cell crisis

30
Q

triggers of sickle cell crisis

A 
high altititude (hypoxia) 
under anaesthesia 
dehydration 
infection 
stress
31
Q

inheritance pattern of sickle cell

hence what are the possible outcomes

A

autosomal recessive

sickle cell trait (1 copy of abnormal gene) - HbAS
sickle cell anaemia (2 copies of abnormal gene) - HbS

32
Q

what is wrong with the haemoglobin in sickle cell

what causes this

A

Bs globin chains instead of B globin chains

mutation in globin chain synthesis

33
Q

what happens to HbS in a sickle cell crisis

A

it polymerises = distorts RBC shape to be sickle cells = RBC damage = haemolysis

34
Q

what do sickle cells do to vasculature

A

vascular occlusion = tissue infarction

35
Q

investigations for sickle cell

A

gel electrophoresis/HPLC (high performance liquid chromatography)
will see raised HbS

36
Q

what type of RBCs are made in sickle cell

A

reticulocytes

sickle cell = haemolysis = reticulocyte formation to compensate

37
Q

presentation of sickle cell anaemia in fingers

A

dactylitis = painful swollen digits (v painful)

38
Q

presentation of sickle cell anaemia in penis

A

priapism - painful erection

39
Q

blood film of sickle cell (3)

A

target cells
sickle cells
reticulocytes

40
Q

acute management of sickle cell crisis

A

hydration
opiate analgesia for pain
red cell exchange transfusion (replace HbS with donor HbA)

41
Q

chronic management of sickle cell anaemia

A

folic acid - bc chronic haemolysis

hydroxycarbamide - induces HbF (fetal haemoglobin) production

J Haem (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions