Thallasemia

Question 1

What is Thalessima?

Answer 1

Genetic inability to produce any of the A or B chains of haemoglobin

Question 2

What is the inheritance pattern of thallasemia?

Answer 2

Autosomal recessive

Chromosome 11

Question 3

What are the four types of alpha thallasemia?

Answer 3

Minina - one gene - carriers

Minor - 2 genes - mild microcytic anaemia

Haemoglobin h - 3 genes - symptoms

four - Fetal death

Question 4

What do A and B thalessemia have in common biochemically and pathogensis wise

Answer 4

Reduced O2 carrying capability Haemolysis of damaged cells

Microcytic anaemia (keep dividing to find right haem concentration). Low MCV

Question 5

What is the difference in pathophysiology of alpha and beta?

Answer 5

Alpha - Insufficient haemoglobin due to excessive B chain formation and abnormal dissociation curves. Can lead to hydrops foetalis if fetus cant make alpha or fetal haemoglobin

Beta - Decreased RBC and production and increased damage due to excessive Alpha chains binding to precursor membranes

Question 6

Why doesnt hydrops foetalis occur in B thallasemia?

Answer 6

Fetal haemglobin is alpha and gamma

Question 7

What is B thallesmia minor or major

Answer 7

Minor - one copy of faulty gene (mild anaemia and normal iron levels)

Major - both copies - Symptoms

Question 8

Where are beta thallasemias common?

Answer 8

People of Italian or Greek descent

Question 9

How many alpha genes are there and how many beta?

Answer 9

4 alpha. 2 beta

Question 10

How many genes code for each A chain?

Answer 10

2, so four per haemoglobin

Question 11

When is thalessemia fatal?

Answer 11

If all four A chains are mutated in pregnancy as A is needed for foetal haemoglobin

Question 12

What are the symptoms of (mild) or moderate thalessemia (Five)

Answer 12

Mild Asymptomatic

Moderate - Anaemia

Microcytosis

Jaundice, hepatpsplenomegaly - Breakdown in RBC in organs

Frontal bossing and maxillary prominence

Shortened limbs and fingers due to ischameia and premature epiphyseal plate closing

Iron overload and cirrhosis

Question 13

What is this?

Answer 13

Hair on end sign for thallasemia or SCA

Question 14

What are the investigations for thalessemia?

Answer 14

Genetic testing

X rays

Bloods - High reticulocytes and microcytic anaemia

Question 15

What is the management for thalessemia

Answer 15

Transfusions

Genetic counselling

Iron chellation/desferroximine

Question 16

What other chemical increases in Sickle cell and Thallasemia?

Answer 16

EPO

Question 17

What is key in B thallesemia?

Answer 17

Increased RBC breakdown

Question 18

What can be a long term consequence of poorly controlled thallasemia?

Answer 18

Liver cirrhosis

Question 19

What is hydrops faetalis?

Answer 19

Fotel death due to alpha thallesemia and the inabilty to make alpha chains or fetal haemoglobin