2. A four years old boy was brought to the pediatric
hospital with a history of severe back pain and
uncontrolled vomiting since previous night. Further
His mother told that her child was complaining
about some attacks of back pain occurring during
the past months.
On examination patient was pale and spleen was
palpable below the costal margin……!!!!
2
3. In investigation,
• Haemoglobin level - decreased
• Peripheral blood smear - sickled cells
- nucleated RBC
-features of microcytic
hypochromic anaemia
• X-ray of the skull – hair on end appearance of
frontal bone
3
4. SICKLE CELL ANAEMIA……????
Inherited.
form of an anaemia as a result of mutation in Hb.
RBC sickled or crescent shaped.
NOT enough healthy RBC to carry adequate
oxygen.
4
5. Normally, humans have
Of these, Haemoglobin A makes up around 96-97%
of the normal haemoglobin in humans.
Haemoglobin
A two alpha two beta
A2 two alpha two delta
F two alpha two gamma
5
6. Common types of Sickle Cell
Disorders
Type of
anaemia
Hemoglobin
variation
comment
Sickle Cell
Anemia
Sickle
haemoglobin
(HbS) + Sickle
haemoglobin
Most Severe –
No HbA
Hemoglobin S-
Beta thalassemia
Sickle
haemoglobin
(HbS) + reduced
HbA
Mild form of
Sickle Cell
Disorder
Hemoglobin S-C Sickle Mild form of 6
8. Pathophysiology
Is caused by
• point mutation in the β-globin chain of Hb
glutamic (hydrophobic amino acid)
valine( hydrophilic )
• at the 6th position
Life span
• RBC 90–120 days
• sickle cells 10–20 days.
10. • exposure to P O2 < 40 mmHg for 2 to 4 minutes
• polymerization of Hb
• The initiation of polymerization may be
-incomplete and
-reversible , if re-oxygenation occurs early in
the process.
• Repetitive exposure to alternating de-
oxygenated and oxygenated states lead to
-membrane distortion,
-irreversible sickling.
17. Sickle solubility test
Mixture of Hb S in a reducing solution
Gives a turbid appearance
(Precipitation of Hb S)
Normal Hb gives a clear solution
17
