Thalassemias are inherited disorders characterized by deficient synthesis of globin chains, resulting in various forms of microcytic hypochromic anemia. The two main types are alpha and beta thalassemia, differentiated by which globin chain production is reduced. Diagnosis involves clinical features, family history, and hematological tests, with manifestations ranging from asymptomatic carriers to severe transfusion-dependent conditions.

1. THALASSAEMIAS

2. Review
Haemoglobinopathies

3. HAEMOGLOBINOPATHIES
 Haemoglobinopathies are ‘inherited abnormalities
of globin chain synthesis’
 Encompass a clinical spectrum from asymptomatic
findings on blood film to death in utero.
 Wide spread distribution throughout the world and
increasing prevalence in multicultural Australia.

4. HEMOGLOBIN STRUCTURE.
 A normal hemoglobin molecule consists of:
 Four globin chains (2 alpha, 2 beta).
 Each globin chain has an iron containing
heme molecule.
 The iron in the heme molecule binds to
oxygen.

5. β
β
α
α
heme
Hemoglobin structure
Hb A tetramer

globin

globin
 globin  globin

6. α
α
α
α α
α
β γ δ
β δ
γ
HbA HbF HbA2
98% ~1% <3.5%
HEMOGLOBINS IN NORMAL
ADULTS

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8. α2Δ2
α2γ2

9. THALASSEMIAS
The thalassemias are a heterogenous
group of congenital anemias that have in
common deficient synthesis of one or
more of the globin subunits of the normal
human hemoglobins (Hbs).

10. CONTI.
Thalassemias are also a group of
microcytic hypochromic anaemias
(MCV & MCH are low) arise as a result of
diminished or absent production of one or
more globin chains.
It is divided on α or β thalassaemia
depending on whether there is reduced
synthesis of α or β globin

11. • Iron deficiency
• Chronic
inflammation or
malignant
Iron Protoporphyrin
Heme Globin
+
Hemoglobin
• Thalassemia
• Sideroblastic
anemia
Hypochromic Anemia

12. DEMOGRAPHICS: THALASSEMIA
• Found most
frequently in the
Mediterranean,
Africa, Western and
Southeast Asia, India
and Burma
• Distribution parallels
that of Plasmodium
falciparum

14. THALASSEMIA
 Heterogenous group of disorders due to
an imbalance of  and  globin chain
synthesis
  thalssemia: -globin chain production
decreased
  thalassemia:  globin chain production
decreased

15. *MAIN TWO TYPES OF THALASSEMIA
ARE:-
1)  thalassemia  thalassemia
2) Note:
3) *There are other types according to genetic classification

16. Thalassaemias are divided clinically into :
Thalassaemia major:
( hydrops fetalis & β-thalassaemia major), which is
transfusion dependent.
Thalassaemia intermedia:
characterized by moderate anaemia usually with
splenomegaly and iron over load.
Thalassaemia minor:
usually asymptomless carrier.
CLINICAL CLASSIFICATION

17. Genetics of Thalassemia

18. CON. THALASSEMIA
 The globin chains that are produced are
normal
 It is characterized by quantitative deficiency,
for example:
 o thalassemia: No -globin chain is made
 + thalassemia: decreased -globin chain is
made
 With 4  genes and 2  genes there is wide
phenotypic variation

19. 1. ALPHA THALASSEMIA
 Normally, there are four copies of the a-globin
gene, therefore the clinical severity can be
classified according to the number of genes that
are missing or inactive.
 In case of alpha thalassemia there is inadequate
production of alpha chains

20. THE GENETICS OF ALPHA-
THALASSAEMIA
 Each a gene may be
deleted or (less
frequently) dysfunctional.
 The orange boxes
represent normal genes,
and the blue boxes
represent gene deletions
or dysftunctional genes.

22. ALPHA THALASSEMIA
There could be an excess of  globins,
leading to the formation of  globin
tetramers (4) called hemoglobin H.
Results in hemolysis, generally shortening
the life span of the red cell.

36. DIAGNOSIS OF THALASSEMIAS
 It is suggested by the clinical features,
clinical history of the patient´ family,
ethnic origin, results of routine
haematological tests, Hb electrophoresis,
and demonstration of red cells inclusions.

37. LABORATORY FINDINGS IN ALPHA
THALASSEMIA
 chains Hgb (g/dl) MCV (fl) RDW
/ Normal Normal Normal
/- 12-14 75-85 Normal
-/- or - -/ 11-13 70-75
- -/-  7-10 50-60
- -/- - - - -

38. RETICULOCYTOSIS IN CASE OF
HEMOLYSIS

39. ALPHA THALASSEMIA WITH HEMOGLOBIN H
VITAL STAIN
Hb H: Golf ball
cells
- in case of 3
alpha genes
deletion, caused
by precipitation
of aggregates of
beta globin
chains.

40. HB-H INCLUSIONS

41. CONT. ALPHA THALASSEMIA
Hemoglobin H-Constant Spring
disease.
Assignment

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