Haemochromatosis

About Haemochromatosis

Haemochromatosis, or GH (Genetic Haemochromatosis), is a genetic disorder causing the body to absorb an excessive amount of iron from the diet: the iron is then deposited in various organs, mainly the liver, but also the pancreas, heart, endocrine glands, and joints.

Normally the liver stores a small amount of iron for the essential purpose of providing new red blood cells with iron, vital for health. When excessive quantities of iron are stored in the liver it becomes enlarged and damaged. Deposits of iron may also occur in other organs and joints, causing serious tissue damage.

For a long time it was believed that the disorder was rare, so GH was seldom considered as a possible diagnosis. However, recent surveys of people of Northern European origin have shown a prevalence of 1 in 400 likely to be at risk of developing iron overload. GH is now recognised as being one of the most common genetic disorders.

The Society was set up to provide support and information for those affected by GH. Members recieve information leaflets, treatment record cards, a 'handbook', quarterly newsletter and the opportunity to attend the AGM and hear medical professionals give their updates. For more information about the society, see the end of the leaflet.

Symptoms

• Chronic fatigue, weakness, lethargy.
• Abdominal pain; sometimes in the stomach region or the upper right hand side, sometimes diffuse.
• Arthritis; may affect any joint but particularly common in the knuckle and first joint of the first two fingers. The bronze fist (diagram right) - is an arthritic symptom typical of haemochromatoisis.
• Diabetes (late onset type).
• Liver disorders; abnormal liver function tests, enlarged liver, cirrhosis.
• Sexual disorders; loss of sex drive, impotence in men, absent or scanty menstrual periods and early menopause in women, decrease in body hair.
• Cardiomyopathy; disease of the heart muscle (not to be confused with disease of the arteries of the heart).
• Neurological/psychiatric disorders; impaired memory, mood swings, irritability, depression.
• Bronzing of the skin, or a permanent tan.

Most of these symptoms are found in other disorders. Chronic fatigue may be ascribed to the after-effects of a viral infection or to psychological causes, and abdominal pain to irritable bowel syndrome. Similarly liver disorders may be put down to excessive alcohol intake, even in someone who is only a moderate drinker. However, if the above symptoms are present, GH should also be considered as a diagnosis.

Most individuals who have GH will, in due course, develop at least one or two of the above symptoms, although possibly in a very mild form. There may be a long phase of the condition where there are no symptoms. However, if arthritis is found only in the first two finger joints this is highly suggestive of GH.

The need for treatment to remove excess iron does not depend upon the presence of clinical symptoms. The risk of developing a serious complaint such as cirrhosis is much too great to be overlooked.

How is it inherited?

Inherited disorders are caused by defective genes in the cells which make up the body. Genes, which are made of DNA, contain the information the body needs to develop from the egg and to maintain itself in good working order. There are about 30,000 genes and every cell in the body, except sperm and egg cells, contains two copies of each. One of these copies is inherited from the mother and one from the father.

In 1996 the HFE gene was identified as the major gene affected in haemochromatosis. A small change (mutation) is present in both copies of the gene in over 90% of those diagnosed with GH. GH is a 'recessive' disorder. The risk of absorbing excess iron will only occur if both copies of the gene are abnormal. If only one copy is defective, an individual will be perfectly healthy but will be a 'carrier'. This means he or she will be able to pass on the abnormal gene to a son or daughter.

Sperm and egg cells have only one copy of each gene, and on average half the eggs or half the sperm of a carrier will contain the defective version. By contrast, ALL the eggs or sperm of an individual in whom both gene copies are defective and who, as a result, suffers from GH, will carry the abnormal gene.

To develop GH you have to inherit a defective gene from both your parents. This can happen in three ways:

1. If both parents are carriers (most common - about 10% of the population are carriers, so 1% of marriages will be between carriers). On average a quarter of the children will develop GH, half will be carriers, and a quarter will be normal.
2. If one parent has GH and the other is a carrier (about 1 in 2000 marriages), on average half the children will develop GH, the other half will be carriers.
3. If both parents suffer from GH, (a rare event, occurring in about 1 in 100,000 marriages) all the children will inherit two defective genes, and will have GH.

It should be emphasised that the proportions given in examples 1 and 2 are averages for the whole population: in any particular family where both parents are carriers (example 1) it would be possible for all children to be affected, all to be carriers, or for all to be normal.

What are the tests?

1. Transferrin Saturation (TS)

TS is the ratio of two simple blood tests, which indicates iron accumulation. Serum iron is divided by total iron binding capacity (TIBC) to give the TS percentage. The test should be performed after an overnight fast. Normal average is 30% (slightly higher in men than women). If on two occasions this is over 55% in men or 50% in women, GH is very likely and one should proceed to measure:

2. Serum Ferritin

This indicates the amount of iron stored in the body. Levels significantly over 300æg/l [micrograms per litre] in men and 200æg/l in women are further evidence of GH. It should be realised that in the early stages of iron accumulation, serum ferritin may be within the normal range. Raised TS with a normal serum ferritin level does not rule out a diagnosis of GH.

3. Gene Test

A simple blood test for the HFE gene mutation is positive in over 90% of those affected. It will identify family members at risk of loading iron.

4. Liver Biopsy

A small sample of the liver is removed using a biopsy needle, which shows whether tissue damage such as cirrhosis is present. It is recommended when the serum ferritin reading is over 1000æg/l, there is evidence of abnormal liver function, or the HFE test is negative.

What is the treatment?

The simple and effective treatment consists of regular removal of blood. Known as venesection therapy or phlebotomy, the procedure is the same as for blood donors. Every pint of blood removed contains a quarter of a gram of iron. The body then uses some of the excess stored iron to make new red blood cells. Venesection will usually be performed once a week, depending on the degree of iron overload. Treatment may need to be continued at this frequency for up to 2 years, occasionally longer.

During the course of treatment, the serum ferritin levels are monitored, indicating the size of the remaining iron stores. Treatment should usually continue until the serum ferritin level reaches 20æg/l (indicating minimal or absent iron stores).

How effective is treatment?

Venesection treatment will cause tissue iron to be mobilised and iron stores will return to normal. However, it will not cure some serious clinical conditions such as diabetes or cirrhosis if they are already present at the time treatment is started. This emphasises the need for early diagnosis.

• Fatigue, lethargy and abdominal pain should decrease.
• Cardiomyopathy should improve providing cardiac damage is not severe. In severe cases iron chelation treatment can reverse congestive heart failure.
• Bronzing of the skin should fade.
• Cirrhosis will stay the same.
• Sexual dysfunction and arthritis do not usually improve. Indeed arthritis may appear later even if absent at the time of diagnosis and treatment.
• Providing there is not a massive, long-standing iron overload present at the time treatment is started; those who undergo treatment have a normal life expectancy.

What about diet?

The Haemochromatosis Society

Hollybush House, Hadley Green Rd, Barnet, Herts, EN5 5PR, England
Phone: 0208 449 1363
Email: info@haemochromatosis.org.uk
Web: www.haemochromatosis.org.uk

Our Aims

+To SUPPORT people with GH by providing help with their problems and ensuring that their relatives are tested in due time. The quarterly newsletter provides news and views from members in the UK and from around the world. Opportunities to meet other members living nearby are arranged if they wish.

+To promote AWARENESS among the health professions, patients and their families, the general public and policy makers so that the condition may be diagnosed and treated in time. There is also a need to overcome the misconceptions that GH is rare, that only middle-aged men are at risk, and women are seldom affected until their menopause.

+To encourage and support RESEARCH, and provide resource material for the allied medical professions. The Society keeps up to date on the latest studies.

Medical Advisors
Professor T. M. Cox, University of Cambridge School of Clinical Medicine
Dr. J. S. Dooley, Centre for Hepatology, The Royal Free Hospital, London
Professor M. J. Pippard, Ninewells Hospital and Medical School, University of Dundee
Professor R. Williams, CBE, Director of the Institute of Hepatology, University College London Medical School

Scientific Advisors
Dr K. Robson, Weatherall Institute of Molecular Medicine, Oxford
Professor M. Worwood, University of Wales College of Medicine, Cardiff
Professor Paul Wordsworth, Nuffield Orthopaedic Centre, Oxford

The Society is a member of the following organisations, the International Association of Haemochromatosis Societies, the Genetic Interest Group and Contact a Family, and is affiliated to the British Liver Trust.

Registered Company Number 2541561
Registered Charity Number 1001307

© Haemochromatosis Society 2008. Used with permission