Introduction - thalassemia for Lab.students

1. INTRODUCTION - Thalassemia
Developed by-Dr.Abdulrazzaq Othman Alagbare
M.D M.S.c C.P - Lecturer of Hematology and Immunohematology

2. Points to remember
Normal of HbA genotype is : / and β/ β,
HbA:, a2 β2 4 genes alpha chains (2 from each parents),
β chains (1 from each parents
Extravascular haemolytic disorders –Removed by macrophages of the RES
inside the spleen
Intravascular haemolytic disorders- completed within the circulatory
system
The HbF replaced by Hb A occurs 3-6 months after birth

3. Homozygous persons:
are severely affected
die early in childhood without
treatment
Heterozygous individuals
Not sever affected
Live long life
Thalassemia Info.
Definition: Thalassemias are a heterogenous group of genetic disorders.
Thalassemia Frequencies .
β thalassaemia is frequent;
a thalassaemia is rare

4. Types of thalassemia
1- a-thalassemia
2-  thalassemia Causes of thalassemia:
1- a-thalassemia  Deletion of a-chains
2-  thalassemia  Mutation of  chains

5. Normal /
β/ β
Normal
Case 1 - /
β/ β
Silent carrier Absent 1 alpha
chain
Heterozygous
alpha thalassemia types:

6. Case 2-1 - /- 
β/ β
Minor alfa
thalassemia
Absent 2 alpha
chains
Homozygous
Case 2-2 - -/
β/ β
Minor alfa
thalassemia
Absent 2 alpha
chains
Heterozygous
alpha thalassemia types:

7. Case 3 - -/- 
β/ β
HbH Absent 3 alpha
chains
Homozygous
Case 4 - - /- -
β/ β
Barts hydrops
fetalis
Absent 4 alpha
chains
Homozygous
alpha thalassemia types:

9. Case 1aa/aa
0/0
Absent 2 beta
chains
Major Beta thalassemia
(Cooley’s anaemia)
Homozygous
Case 2aa/aa
/0
Absent 1 beta
chains
Minor Beta thalassemiaHeterozygous
0 :Indicates no production of globin chain by gene
+: Indicates diminished, but some production of globin chain by gene:
defects in production of Hb ß that leads to microcytosis
β-thalassaemia types

10. Types of beta thalassemia
When β chains is designated as
•β  normal beta chain production
•β0,  no production beta chains
•β+  partially produce beta chain
-thalassemia types Details:

11. -thalassemia mutant genes
At least three different mutant genes are involved:
•+1 – 10% of normal  chain synthesis occurs
•+2 – 50% of normal  chain synthesis occurs
•+3 - > 50% of normal  chain synthesis occurs
-thalassemia types Details:

12. ‫رب‬ ‫هلل‬ ‫الحمد‬
‫العالمين‬
‫به‬ ‫ابتغي‬ ‫هذاعمل‬
‫الكريم‬ ‫هللا‬ ‫وجه‬
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