Hereditary Hemochromatosis (HH) is the most common genetic disorder of persons of northern European extraction. The most common gene involved in causing Hereditary Hemochromatosis (HH) is the HFE gene. Most patients with hemochromatosis have two copies of the HFE mutation C282Y.
In persons of northern European extraction approximately 1 in 10 persons carries one copy of C282Y. Even one copy of C282Y can be associated with too much iron in the liver, high cholesterol, diabetes and the skin disorder porphyria cutanea tarda.
Approximately 1 in 200 to 300 persons of northern European extraction carry two copies of C282Y. In some northern European populations eg Ireland, Iceland and Brittany the percentage of persons carrying one copy of C282Y is higher. Predictably countries settled by northern Europeans eg Australia, South Africa and Canada have high rates of hemochromatosis.
HH is characterised by excessive absorption of dietary iron and a consequent progressive increase in total body iron stores. Iron accumulates in the parenchymal cells of the liver, the heart, pancreas, anterior pituitary and skin. This accumulation of iron in body tissues causes disease.
In severe HH the disorder manifests as potentially life threatening conditions such as septicaemia, cirrhosis of the liver, liver cancer, diabetes, heart failure and heart arrhythmias. Arthritis is common and a severe arthritis involving numerous joints may occur. Ovarian and testicular failure secondary to iron deposition in the anterior pituitary and possibly the hypothalamus may occur. Rarely hypothyroidism may occur.
If HH is not treated liver disease may be fatal. The morbidity and mortality of HH can be reduced by early diagnosis and treatment by phlebotomy or blood letting.
There is frequently a delay between the onset of symptoms and diagnosis. This is because early symptoms such as fatigue and arthralgia are non-specific.
Hereditary Hemochromatosis fits the criteria set by the World Health Organisation for population screening for a disease:
- The homozygous genotype is common and is potentially fatal if not treated
- The disease has a lengthy latent period with asymptomatic iron accumulation followed by a period of iron overload with reversible organ injury
- Treatment during the latent period and the period with reversible organ injury restores the life expectancy to normal. (Treatment is safe, effective and cost effective)
- HH can be detected by measurement of the transferrin saturation (TS).
It is very important to make an early diagnosis of HH because patients who have not developed cirrhosis and are treated by phlebotomy have a normal life expectancy.
When the diagnosis of hemochromatosis is made it is important to adjust the diet so that too much iron is not being absorbed because of an improper diet.
- The biggest considerations are not to take medications which contain iron, consume too much alcohol or Vitamin C.
- The ingestion of black tea has been shown to decrease the absorption of iron.
- African tea which is becoming popular may contain iron so too much should not be consumed.
- Don’t take milk thistle which has often been touted as good for the liver as it can cause severe problems in those with hemochromatosis.
- Don’t eat raw shellfish. They may be contaminated with Vibrio vulnificans which thrives in an iron rich environment. There have been fatalities in the northern hemisphere. Cooking inactivates this organism.