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Question 1

sickle cell is a

Answer 1

monogenetic condition

Question 2

it is cause by a

Answer 2

single base mutation

Question 3

when was it discovered

Answer 3

in 1910

Question 4

what is the result of the disease?

Answer 4

it is the result of homozygous and compound heterozygote inheritance
of a mutation in the β-globin gene

Question 5

What does this mutation causes?

Answer 5

A single base-pair point mutation (GAG to GTG) results in the
substitution of the amino acid glutamic acid (hydrophilic) to Valine (hydrophobic) in the 6th position
of the β-chain of haemoglobin referred to as haemoglobin S (HbS

Question 6

common type of sickle cell

Answer 6

The inheritance of homozygous HbS otherwise referred to as sickle cell anaemia (SCA) is the most
predominant form of SCD

Question 7

sickle cell

Answer 7

in certain regions 1/4 individuals are carriers of the disease.

Question 8

in LICs

Answer 8

50-90% die within first 5 years

Question 9

causes of young death

Answer 9

Among the common causes of death in the absence of
early diagnosis followed by education and preventive therapies such as penicillin prophylaxis and
regular surveillance include infections, severe anaemia (acute splenic sequestration, aplastic anaemia)
and multi-organ failure

Question 10

what happens to the RBCs

Answer 10

when

exposed to deoxygenated environment undergo polymerisation and become rigid

Question 11

what do the RBC causes

Answer 11

The dense rigid RBC’s lead to vaso-occlusion, tissue ischaemia, infarction as well as
haemolysis

Question 12

complications

Answer 12

complications such as leg ulceration, stroke, pulmonary hypertension and priapism

Question 13

RBCS lifespan of SCD

Answer 13

10-20 days due to Haemolysis

Question 14

what affects the individual with SCD

Answer 14

Pain. this leads to many hospital visits. it is unpredictable.

Question 15

Pain causes

Answer 15

Pain occurs due to stimulation of nociceptive nerve fibres caused by microvascular occlusion. The
microcirculation is obstructed by sRBCs, thereby restricting the flow of blood to the organ

Question 16

pain in infants

Answer 16

Infants display their pain
nonverbally with irritability and apparent ‘regression’ tendencies such as inability to weight bear, walk
or crawl.

Question 17

triggers to pain

Answer 17

The onset of
pain is spontaneous, usually no precipitating factors; well-known triggers include infections, fever,
dehydration, acidosis, sudden change in weather including wind speed, cold, rain and air pollution.
Resolution of pain is unpredictable. Acute pain might lead to chronic pain

Question 18

diseases

Answer 18

SCD increases susceptibility to infections, notably bacterial sepsis and malaria in children under
five years

Question 19

social effects of SCD

Answer 19

SCD has a significant psychosocial impact on patients and families [53]. This mainly results from
the effect of pain and symptoms on their daily lives, and society’s attitudes towards them. Cultural
factors are particularly important to these problems because of beliefs and practices [54]. Furthermore,
the ability of people with SCD to cope with their condition varies greatly because severity, general
health, and quality of life varies greatly among individuals [5

Question 20

Treatment

Answer 20

SCD causes a range of acute and long-term complications, requiring a multi-disciplinary approach,
involving various medical specialists. In the United Kingdom, comprehensive SCD care is coordinated
by specialist haemoglobinopathy teams

Question 21

Education

Answer 21

Such teams play a key role in education about SCD for
patients and their families, as well as guiding treatment with disease-modifying therapies, access
to psychology, social and welfare support

Question 22

mild pain

Answer 22

can be dealt at home .

self psychological help.

Question 23

medical treatment so far

Answer 23

Currently the only available disease-modifying medications for SCD are hydroxycarbamide and
l-glutamine.

Another effective disease modifying therapy is blood transfusion to raise the haemoglobin
for improved oxygenation in severe anaemia and also to reduce the proportion of sickle haemoglobin
(HbS%) may be give as a simple top-up blood transfusion or as exchange transfusion (manual or
automated).

The main curative therapy is stem cell transplantation while gene therapy is in the horizon
in clinical Trials

Question 24

Hydroxycarbamide

Answer 24

reduces the number of leucocytes in blood, and reduces
expression of surface adhesion molecules on neutrophils, red cells and vascular endothelium resulting
in improved blood flow and reducing vaso-occlusion

Question 25

Blood Transfusion

Answer 25

Blood transfusions are not given to correct this baseline anaemia or for acute pain episodes.

Instead, transfusions are given to correct acute severe anaemia where the haemoglobin falls significantly below
that individual’s baseline, and the resulting impairment in oxygen delivery to body tissues would
otherwise propagate further sickling of deoxygenated Hb

Question 26

BMT

Answer 26

BMT is the only current cure for SCD and is one of the newer methods of treatments available.
Results indicate an event-free survival rate of approximately 91% and a mortality rate of less than
5%

Question 27

Risks of BMT

Answer 27

Other risks from undergoing BMT include strokes, fatal infection, organ
damage, and fits

Question 28

. Treatments that Reduce HbS Polymerisation

Answer 28

GBT440 (Voxelotor) is an oral small molecule designed to increase the oxygen affinity of HbS,
shifting the oxygen dissociation curve of oxy-HbS to the left

Question 29

. Nutritional Supplements

Answer 29

Omega-3 fatty acids have been purified from fish oil and tested for benefits as antioxidant,
antithrombotic, and anti-inflammatory benefit

Question 30

Herbal products

Answer 30

A traditional herbal product used to treat SCD in Nigeria, Niprisan, showed promising pre-clinical
data although it is likely to have drug interactions from its significant inhibition of cytochrome CYP3A4
activity.

Question 31

. Gene Therapy

Answer 31

he approach is based
on stem cells and gene therapy; instead of using embryonic stem cells, host stem cells are derived by
manipulating and reprogramming cells from patient’s own blood cells with genetic engineering used
to correct the inborn genetic error