Sickle cell Anaemia and Thalassemia Flashcards
What is the pathophysiology of both Sickle Cell Anaemia and Thalassaemia
They are both inherited disorders of haemoglobin production (and therefore genetic diseases)
What is haemoglobin
It is an essential metaloprotein tetramer
Where is haemoglobin made
Nucleated rbcs within the bone marrow
What is it made of
Haem plus 2alpha and 2beta type proteins
Describe the stages of protein synthesis
Genes of chromosomes code for proteins
On what chromosomes are the genes for alpha and beta chains in haemoglobin made
Alpha on CH 16; Beta on CH 11
Name the two major components of haem
iron and protoporphyrin
What are the three main structures in rbcs
membrane, enzymes and haemoglobin
Why does iron deficiency lead to microcytic anaemia
The rate of cell division is controlled by the HB concentration. If there is iron deficiency or insufficient globin chains there will be a decrease in the [Hb]. The result is that there are more divisions and so the cells are smaller.
Name one cause of macrocytic anaemia
Vit B12/Folate deficiency
Why does vit B12/Folate deficiency lead to larger rbcs
Vit B12/Folate deficiency interferes with the DNA replication. DNA is essential for mitoses to occur. With less DNA there are fewer divisions so the resulting cells are bigger.
