Normally, the body maintains a steady level of iron. The iron is absorbed from food and the amount absorbed varies according to the body's need for it.
People with haemochromatosis cannot control levels of iron in their bodies in this way. As a result, iron builds up over time and is usually deposited in the liver, pancreas, joints, heart or endocrine glands.
A faulty gene called HFE causes haemochromatosis. Everyone receives two sets of genes – one from their father and one from their mother. If a person receives a set that includes the mutated HFE gene, they will not develop symptoms but they will be a carrier of the HFE mutated gene. In some ethnic groups, such as people of Irish descent, as many as one in 10 may be a carrier of the HFE mutation.
If a carrier of the mutation has a baby with a fellow carrier there is a significant chance the baby will receive two sets of mutated genes and develop haemochromatosis.
The likelihood of the child being affected is as follows:
- there is a one in four chance that the baby will receive a pair of normal HFE genes and be unaffected
- there is a one in two chance that the baby will receive one normal HFE gene and one mutated HFE gene – this means they will not have haemochromatosis but they will be a carrier of the condition
- there is a one in four chance that the baby will receive a pair of mutated HFE genes – this means they will develop haemochromatosis later in life
