Thalassaemia is the name of a group of genetic conditions that affect haemoglobin production and, as a result, red blood cell size.

In a small proportion of children presenting with anaemia, there may be an underlying genetic cause.

Affected patients will have a variety of distinctive features and a progressive reduction in the production of normal blood cells in the bone marrow, which results in pancytopenia and an increased chance of developing certain cancers.

Pancytopenia is a condition in which a person has too few red blood cells, white blood cells and platelets. In some children presenting with pancytopenia, there will be a genetic cause.

Sickle cell disease is a genetic disorder that causes abnormal polymerisation of haemoglobin, brought on by triggers such as low oxygen levels or reduced temperature. It is named after the characteristic sickle-shaped red blood cells.

Fanconi anaemia is a heritable bone marrow failure syndrome caused by problems with the body’s chromosomal repair systems.