thalassemia vignette

Question 1

hemoglobin genes

Answer 1

16p13. 3

11p15. 5

Question 2

globin synthesis during development

before birth

Answer 2

high alpha and gamma

low beta

Question 3

glob in synthesis after birth

Answer 3

alpha stays high

beta rises about 3 months
gamma goes down

Question 4

Qualitative hemoglobinopathies

Answer 4

• Hb S
• Hb C
• Hb E

Question 5

Quantitative hemoglobinopathies Thalassemias

Answer 5

α thalassemia
β thalassemia
γ thalassemia
Δthalassemia

Question 6

Hemoglobin S

Answer 6

Hemoglobin S

a) Homozygous SS disease “Sickle Cell Anemia”
b) S heterozygous: AS, sickle trait
c) Sickle Syndromes:
1) Hemoglobin SC hemoglobinopathy
2) SB° thalassemia
3) SB+ thalassemia

Question 7

Hemoglobin C

Answer 7

a) Homozygous CC hemoglobinopathy
b) Heterozygous C, e.g. AC, or C trait
c) C-Beta thalassemia

Question 8

Hemoglobin E

Answer 8

a) Homozygous EE
b) Heterozygous AE
c) Combination: E-Beta thalassemia

Question 9

Hemoglobinopathies

Answer 9

269 million carriers of hemoglobin disorders in the world:
-15% of Africans are S carriers
-7% of SE Asians are E carriers
-4-5% of SE Asians and Mediterranean population are beta thal carriers
-350,000 babies are born throughout the world each year with major hemoglobin disorders
Majority of the children die undiagnosed, untreated or under-treated

Question 10

SE Asia:

Answer 10

SE Asia: α, β thalassemia and E

Question 11

Africa –

Answer 11

Africa – S, C, α and β thalassemia

Question 12

West Pacific

Answer 12

West Pacific – α and β thalassemia and E

Question 13

East Mediterranean

Answer 13

– β thalassemia and S

Pa

Question 14

Thalassemia is a

Answer 14

disorder in which a reduced rate of one or more of the globin chain synthesis leads to imbalanced globin chain production, defective hemoglobin production and damage to the red cells and their precursors.

Question 15

αThalassemia types:

Answer 15

a) α thalassemia major
b) α thalassemia 3 gene deletion (Hgb H disease)
c) α thalassemia 2 gene deletion (α thalassemia trait)
d) α thalassemia 1 gene deletion – clinically insignificant
e) α thalassemia + Hgb Constant Spring

Question 16

β Thalassemias:

Answer 16

β Thalassemias:

a) β thalassemia major “Cooley’s anemia”
b) β thalassemia intermediate c) β thalassemia trait
d) SB° thalassemia
e) SB+ thalassemia

Question 17

Y Thalassemia:

Answer 17

Y Thalassemia: Clinically significant only at birth and usually over by 6 months of life.

Question 18

δ Thalassemia:

Answer 18

δ Thalassemia: Not significant by itself but can be a problem if β-δ thalassemia.

Question 19

B thalassemia clinical features

Answer 19

1. dense skull/marrow expansion
2. enlarged spleen
3. osteopenia/bone changes
4. iron overload
5. growth and endocrine features