Haematology 16: Paediatric Haematology

Question 1

What is Transient abnormal myelopoiesis ?

Answer 1

• Congenital form of leukaemia commonly affecting children with Down syndrome.
• Tends to remit within the first 2 months of life
• Mainly affecting megakaryocyte lineage

Question 2

On which chromosome is the ß cluster ?

Answer 2

Chromosome 11

Question 3

On which chromosome is the å cluster ?

Answer 3

Chromosome 16

Question 4

Which Globin chains make up HbA ?

Answer 4

å2ß2

Question 5

Which Globin chains make up HbA2 ?

Answer 5

å2∂2 (alpha and delta)

Question 6

Which Globin chains make up HbF ?

Answer 6

alpha 2 gamma 2

Question 7

Why does Sickle cell disease not present in the first 6 months of life ?

Answer 7

HbF is still in high concentration and is able to compensate

Question 8

Name the test used to diagnose sickle cell anaemia at birth ?

Answer 8

The Guthrie spot test

Question 9

Why do children with sickle cell experience hand-foot syndrome whereas adults get bone pain in the central skeleton?

Answer 9

• Red bone marrow (where red blood cells and leukocytes are produced) is only present in the central skeleton in adults but in all bones in children.
• Sickle cells cause infarction of the vessels that supply the bone marrow causing pain

Question 10

What happens if a child with sickle cell anaemia gets a parvovirus b19 infection ?

Answer 10

Aplastic anaemia

Question 11

What are some of the clinical features of thalassaemia Major ?

Answer 11

Bossing of facial bones
Hepatosplenomegaly
Iron overload- heart/liver failure
Growth retardation

Question 12

What is the main treatment for vWD ?

Answer 12

Factor 8 concentrates

Question 13

What is the most common leukaemia of childhood ?

Answer 13

ALL

Question 14

differences in neonatal bloods

Answer 14

high WCC, neutrophils, lymphocytes, Hb and MCV, higher percentage HbF, lower G6PD concentration

Question 15

causes of fetal polycythaemia

Answer 15

twin-to-twin transfusion
intrauterine hypoxia
placental insufficiency

Question 16

causes of fetal anaemia

Answer 16

twin-to-twin transfusion
foetal-to-maternal transfusion
parovirus infection
haemorrhage from cord or placenta

Question 17

features of leukaemia in utero

Answer 17

congenital leukaemia common in DS 
= TAM (transient abnormal myelopoiesis 
remits spontaneously within the first 2 months of life 
relapses 1-2 yrs 
myeloid leukaemia

Question 18

what is thalassamia

Answer 18

condition resulting from a reduced rate of synthesis of one or more of the globin genes

Question 19

what is a haemoglobiopathy

Answer 19

structurally abnormal haemoglobin

Question 20

what chromosomes are the globin chains controlled by

Answer 20

chromosomes 11 and 16 
chr 11:
- beta gene
- delta gene
- gamma gene
- LCR (locus control region)

chr 16:

• 2 x alpha genes
• zeta gene

Question 21

list the different forms of Hb

Answer 21

A - a2b2
A2 - a2d2 (<3.5% of total adult Hb)
F - a2y2

Question 22

describe Hb in utero

Answer 22

HbF predominated
until 32 weeks - rapid increase in Hb A
at birth 1/3 haemoglobin is HbA

Question 23

features of SCA

Answer 23

SCA = homozygous HbS gene 
SCD = homozygous and heterozygous states 

hypoxia leads to poymerisation of HbS - crescent RBC and blocked blood vessels
post-capillary venules

Question 24

what are howell-jolly bodies a feature of

Answer 24

hyposplenism

Question 25

what is the difference between adult and child in splenic sequestration

Answer 25

infant still has a functioning spleen splenic sequestration - acute pooling of circulating rec cells in the spleen leads to anaemia, shock, death

Question 26

describe vaso-occlusion in the first decade of life in SCA

Answer 26

hand-foot syndrome - 1st 2 yrs acute chest syndrome - infarction in the ribs and lungs painful crises stroke

Question 27

describe spleen problems and bacteraemia in the first decade of life with SCA

Answer 27

splenomegaly hyposplenism acute splenic sequestration bacteraemia

Question 28

what infections are children with SCA especially vulnerable to

Answer 28

pneumococcus parovirus - aplastic anameia prevent with vaccination and penecillin

Question 29

why do children with SCA have increased folic acid demands

Answer 29

hyperplastic erythropoiesis growth spurts red cell lifespan is shortened so anaemia can rapidly worsen

Question 30

treatments for SCA

Answer 30

establish a diagnosis educate parents vaccinate folic acid and penecillin

Question 31

features of childhood beta thalassaemia

Answer 31

``` manifests after first 6m guthrie spot test trait = harmless homozygosity - severe anaemia fatal in 1st few years without blood transfusion ``` poorly treated - anaemia (HF, growth retardation), erythropoietin drive (bone expansion, hepatomegaly, spleno), iron overload (HF, gonadal failure)

Question 32

list 4 triggers of haemolysis in G6PD deficiency

Answer 32

infections drugs napthalene fava beans (X linked)

Question 33

what parts of the history are important with suspected inherited defect of coagulation

Answer 33

``` child history - umbilical cord bleeding / on guthrie test, hematoma after it K injection, bleeding after circumscision family history coagulation screen platelet count assays of coagulation factor ```

Question 34

presentation of VWD

Answer 34

mucosal bleeding bruises post-traumatic bleeding DDx - haemophilia A

Question 35

presentation of haemophilia A and B

Answer 35

bleeding following circumscision haemarthroses bruises post-traumatic bleeding

Question 36

presentation of AITP

Answer 36

petechiae bruises blood blisters in mouth

Question 37

how is hyposplenism managed

Answer 37

vaccinations | prophylactic penecillin