thalassaemia

Question 1

pathology

Answer 1

genetic defects in alpha or beta chain - resulting in alpha thalassaemia or beta thalassaemia
- autosomal recessive
- results in varying types of haemolytic anaemia
- rbc are more fradgile and break down more easily
- also causes splenomegaly

Question 2

Features

Answer 2

Microcytic anaemia (low mean corpuscular volume)
Fatigue
Pallor
Jaundice
Gallstones
Splenomegaly
Poor growth and development

Question 3

Investigations

Answer 3

• 1st line FBC - microcytic anaemia
• raised ferritin - iron overload
• haemoglobin electropheresis - blobin abnormalities - gold standard
• dna testing

Question 4

why might iron overload occur in thalassaemia

Answer 4

Increased iron absorption in the gastrointestinal tract
Blood transfusions

Question 5

iron overload symtpoms and complications

Answer 5

Liver cirrhosis
Hypogonadism
Hypothyroidism
Heart failure
Diabetes
Osteoporosis

Question 6

alpha thalassaemia

Answer 6

• chromosome 16
• sebveity depends on type and number of defects
• no symtpoms - carrier
• moderate anaemia - haemoglobin H disease
• intereuterine death - alpha thallasaemia major

Question 7

alpha thalassaemia management

Answer 7

Monitoring
Blood transfusions
Splenectomy may be performed
Bone marrow transplant can be curative

Question 8

Beta-Thalassaemia

Answer 8

• chromosome 11
• either abnormal copies that retain sme function or deletion genes w no function

3 types:
- Thalassaemia minor (1 abnormal B-globin gene) - mild anaemia

• Thalassaemia intermedia
  (2 abnormal B-gene) worse microcytic anaemia and possibly need iron chelation

Thalassaemia major
homozygous for delection gene - severe anaemia - enlarged maxilla and frontol bossing

Question 9

Diagnosis of thalassaemia (3)

Answer 9

• FBC + blood film
• Hb electrophoresis - diagnostic
• Xr - “hair on end” skull

Question 10

FBC and blood film in thalassaemia (3)

Answer 10

• Hypochromic (pale) RBCs
• Target cells
• Microcytic anaemia with high reticulocytes

Question 11

Presentation of thalassaemia (4)

Answer 11

• Failure to thrive
• Hepatospenomegaly
• Gallstones
• Chipmunk face

Question 12

Signs specific to thalassaemia

Answer 12

Bone deformities

Question 13

What is Iron chelation and what are its side effects? (3)

Answer 13

• Prevents Fe overload from transfusions
• Desfemoxamine
• SE: deafness, cataracts

Question 14

Where is thalassaemia prevalent?

Answer 14

Where malaria is as it is protective from it (like sickle cell)

Question 14

Management

Answer 14

minor cases - treatment not required

major cases - frequent blood transfusion

other options:
Splenectomy
Haematopoietic stem cell transfusion