Haeminoglopathies

Question 1

what chains make up HbA (most abundant)

Answer 1

2 alpha 2 beta globin chains

Question 2

what chains make up HbA2

Answer 2

2 alpha 2 delta chains

Question 3

what chains make up HbF

Answer 3

2 alpha 2 gamma

Question 4

which chromosome codes for alpha globin

Answer 4

16

Question 5

which chromosome codes for beta globin

Answer 5

11

Question 6

which countries are more likely to be affected my thalassamia

Answer 6

mediterranian, north africa, china, vietnam

Question 7

symptoms thalassaemia

Answer 7

microcytic anaemia // jaundice, gallstones, splenomegaly (haemolysis) // poor growth // expanded forehead (bone marrow)

Question 8

how many genes account for alpha Hb

Answer 8

4

Question 9

what type of Hb is affected in alpha thalassaemia

Answer 9

all - HbA, HbA2, HbF

Question 10

how many genes are affected in alpha-trait thalassaemia

Answer 10

1 (aa/a-) or 2 (a-/a-)

Question 11

bloods alpha-trait thalassaemia

Answer 11

hypochromic, microcytic - normal Hb

Question 12

genes affected in haemoglobin H disease

Answer 12

3 defective genes (a-/–)

Question 13

bloods and symptoms haemoglobin H disease

Answer 13

hypochromic, microcytic // excessive HbF // splenomegaly + jaundice

Question 14

genes hydrops fetalis

Answer 14

all 4 alpha genes affeceted (–/–)

Question 15

symptoms hydrops fetalis

Answer 15

death in utero

Question 16

mx alpha thalassaemia

Answer 16

bone marrow transplant

Question 17

inheritence beta thalassaemia trait

Answer 17

recessive

Question 18

mutation in beta-thalassaemia trait

Answer 18

point mutation –> reduced (B+) or absent (B0) production of beta globin

Question 19

what type of Hb is affected in beta thalassaemia

Answer 19

HbA only (a2b2)

Question 20

bloods beta trait thalassaemia

Answer 20

mild hypochromic, microcytic anaemia (VV low MCV compared to slight low Hb) // raised HbA2 as compensation

Question 21

what genes are affected in beta-trait thalassaemia

Answer 21

still have one fully function B gene eg (B/B+ or B/B0)

Question 22

genes affected beta-intermediate thalassaemia

Answer 22

some production but both genes affected (B+/B+ or B0/B+)

Question 23

genes affected + consequences beta-thalassaemia major

Answer 23

both genes have no production (B0/B0)–> absence of beta globulin chains

Question 24

symptoms beta-thal major

Answer 24

presents in first month of life // failure to thrive // splenomegaly

Question 25

bloods beta-major thal

Answer 25

raised HbA2 + HbF // no HbA

Question 26

mx beta-thal major

Answer 26

repeat transfusion // transplant

Question 27

RF + mx of repeat transfusions

Answer 27

iron over load + death // iron chelating therapy eg desferrioxamine

Question 28

what globin chain is affected in sickle cell anaemai and what Hb is formed as a result

Answer 28

point mutation B chain to make HbS

Question 29

sickle cell trait genes

Answer 29

(B/Bs)

Question 30

symptoms sickle cell trait

Answer 30

may get symptoms at high altitude, can still form some normal HbA

Question 31

genes sickle cell disease

Answer 31

hbSS (Bs/Bs)

Question 32

what is sickle cell protective of

Answer 32

malaria - common in afro-carribean people

Question 33

risks with sickle cell disease

Answer 33

blood vessel infarction

Question 34

invx sickle cell disease

Answer 34

Hb electrophoresis (screened for in newborn heel prick)

Question 35

bloods sickle cell anaemia

Answer 35

low hb, microcytic, hypochromic, haemolysis --> bilirubin // blood film

Question 36

symptoms sickle cell anaemia

Answer 36

hyposplenism, jaundice, sickle crisis

Question 37

longterm mx sickle cell anaemia

Answer 37

hydroxyurea (increased HbF)

Question 38

when does sickle cell anaemia present

Answer 38

first few months of life (when HbF falls)

Question 39

what vaccine do sickle cell patients need

Answer 39

pneumococcal every 5 years (bc of hyposplenism)

Question 40

4 main type of sickle crisis

Answer 40

thrombotic or painful // acute chest // aneamic (aplastic or sequestration) // infective

Question 41

what can cause thrombotic. painful/ vaso-oculsive crisis

Answer 41

infection, dehydration, low PO2 (eg altitude)

Question 42

invx thrombotic crisis

Answer 42

clinically

Question 43

sites of thromotic sickle crisis

Answer 43

AVN of hip, hand and foot (kids), lungs, spleen, brain

Question 44

what is acute chest crisus

Answer 44

vaso-occlusion of pulmonary vasculature --> infarction of lungs

Question 45

symptoms + findings acute chest crisis

Answer 45

SOB, chest pain, CXR infiltrates, hypoxic

Question 46

mx acute chest chest crisis

Answer 46

pain relief // o2 // abx // transfusion

Question 47

what is sickle aplastic anaemic crises + what bloods are seen

Answer 47

parvovirus --> bone marrow suppression --> low Hb + low reticuloytes

Question 48

what is sickle sequestrian anaemic crises + what bloods are seen

Answer 48

occlusion in spleen or lungs --> pooling of blood --> worsening anaemia --> increased reticulocytes

Question 49

mx sickle cell crisis

Answer 49

opioids, fluid, O2 (+/-abx_ // blood transfusion // exchange transfusion

Question 50

when is blood transfusion indicated in sickle cell crisus

Answer 50

severe or symptomatic anaemia // pregnancy // pre-operative

Question 51

effect of blood transfusion on HbS

Answer 51

does not rapidly reduce

Question 52

indications exchange transfusion sickle cell crisis

Answer 52

acute vaso-occlusive crisus eg stroke, ACS, organ failure, spleen sequestion

Question 53

effect of exchange transfusion onHbS

Answer 53

rapid fall in HbS