Sickle Cell Anaemia

What is Sickle Cell Anaemia?

An inherited condition used as the required Cambridge O Level Biology example of a gene mutation. A change in the base sequence of the gene coding for haemoglobin alters the amino-acid sequence of the protein. The altered haemoglobin molecules attach to one another inside the red blood cell, which changes the cell's shape from a rounded disc to a curved sickle. Sickled cells carry less oxygen than normal red blood cells and can obstruct small blood vessels. Because it results from a change within one gene rather than a change to a whole chromosome, it is classified as a gene mutation.

This definition is part of the Inheritance chapter in Cambridge O Level Biology.

Concepts related to Sickle Cell Anaemia

• gene mutation
• haemoglobin
• Red Blood Cell
• protein shape