Hemoglobinopathies: sickle cell disease, thalassemias

Question 1

What are they?

Answer 1

(autosomal recessive) disorders arising form point
mutations in gene coding for beta chain of haemoglobin on chromosome 11 or on
alpha chain on chromosome 16.

Question 2

What are functional changes?

Answer 2

• reduced solubility, reduced stability, or altered

oxygen affinity

Question 3

Unstable hemoglobinopathies caused by:

Answer 3

1. Non-polar amino acid in heme-pocket exchanged for a polar amino acid.
2. Mutation leads to alteration of contact residue.

Question 4

Sickle cell disease is a disorder of

Answer 4

blood caused by an inherited abnormal haemoglobin. Irregular sickled cells can also block blood vessels causing tissue + organ
damage + pain

Question 5

Thalassemia’s are

Answer 5

Inherited autosomal recessive blood disorder
- Characterized by abnormal formation of haemoglobin
- Results in improper oxygen transport
- Caused by missing genes (missense mutation) effecting production of
haemoglobin
- Hence fewer RBC circulating in blood - ANEMIA