Hemochromatosis (also called genetic hemochromatosis or hereditary hemochromatosis) is a genetic and hereditary disease responsible for excessive intestinal iron absorptionand accumulation in the body.
Causes of hemochromatosis
Hemochromatosis is a genetic disease linked to a mutation of one or more genes. These mutations are observed in different regions of the globe and each corresponds to a more or less serious expression of the disease.
The hemochromatosis hereditary HFE (also called hemochromatosis type I) is the most common form of the disease. It is linked to a mutation of the HFE gene located on chromosome.
Frequency of the disease
Hemochromatosis is one of the most common genetic diseases.
About 1 in 300 people carry the genetic abnormality that predisposes them to the onset of the disease. But what must be understood now is that the disease may have a variable clinical expression, so that severe forms of hemochromatosis remain rare.
People affected by the disease
The men are more often affected than women (3 men to 1 woman).
The symptoms appear most often after 40 years but can begin between 5 and 30 years (juvenile hemochromatosis).
The disease is more common in some parts of the world, for example in the United States or in Northern Europe. It is not found in the countries of Southeast Asia or in the black population.
In France, some regions (Brittany) are more affected.
What are the symptoms of hemochromatosis?
The symptoms are iron deposits on different organs such as skin, heart, endocrine glands and liver.
Evolution of the symptoms of the disease
– Between 0 and 20 years, iron accumulates gradually in the body without causing symptoms.
– Between 20 and 40 years, appears an iron overload that still does not give symptoms.
– Towards the middle of the fourth decade in men (and later in women), appear the first clinical signs of the disease: permanent fatigue , joint pain (small joints of the fingers, wrists or hips), browning of the skin ( melanoderma), “greyish, metallic” appearance of the skin on the face, large joints and genitals, cutaneous atrophy (skin refines), squamous or fish scale appearance (this is what is calls a ichthyosis) of the skin and a rarefaction of the hair and pubic hair
– When the diagnosis of the disease has not been made, the complications appear affecting the liver, the heart and the endocrine glands.
Impairment of the liver: On clinical examination, the doctor may notice an increase in the volume of the liver, which causes abdominal pain. The cirrhosis and the onset of liver cancer are the most serious complications of the disease.
Endocrine gland involvement: the course of the disease may be enameled by the occurrence of diabetes (pancreatic disease) and impotence in humans (testicular involvement).
Reaching the heart: the iron deposits on the heart are responsible for an increase in volume and signs of heart failure .
Thus, if the disease is diagnosed only at a late stage (cases that remain exceptional today), it is possible to observe the association of heart failure, diabetes and cirrhosis of the liver. and a brownish coloring of the skin.
The earlier the disease is diagnosed (before the age of 40), the better the response to treatment and the prognosis for the disease. On the other hand, when the complications described above appear, they regress little under treatment. If the patient is treated before the onset of cirrhosis, his life expectancy is identical to that of the general population.
The diagnosis of hemochromatosis
The diagnosis can be made during a screening or when the patient has clinical signs suggestive of the disease.
Given the frequency and severity of the disease, it is warranted to detect the disease in persons with a family member who has hemochromatosis. This screening is done by determining the transferrin saturation factor and a genetic test in search of the responsible genetic mutation. A simple blood test is enough:
a rise in the level of iron in the blood (greater than 30 μmol / l) associated with an increase in the saturation coefficient of transferrin (a protein that transports iron in the blood) greater than 50% makes it possible to diagnose the disease. Ferritin (iron stores protein in the liver) is also increased in the blood. The demonstration of liver iron overload no longer requires the practice of a liver biopsy, nuclear magnetic resonance imaging (MRI) is the exam of choice today.
Above all, highlighting the mutation of the HFE gene is the test of choice for diagnosing the disease.
Other complementary examinations make it possible to assess the function of other organs that may be affected by the disease. Assays for transaminases, fasting blood glucose, testosterone (in humans) and an ultrasound of the heart can be performed.
Risks of transmission to children
The transmission of familial hemochromatosis is autosomal recessive, which means that only children who have received the mutated gene from their father and mother are affected by the disease. For a couple who have already given birth to a child with the disease, the risk of having another child is 1 in 4
Risks for other family members
First-degree relatives of a patient have a risk of being carriers of the altered gene or of having the disease. That is why, in addition to the determination of the saturation factor of transferrin, a genetic screening test is proposed to them. Only adults (over 18 years) are involved in screening because the disease does not occur in children. In cases where a person is affected in the family, it is therefore advisable to consult a medical genetics center for an accurate assessment of the risk.
Treatment, management, prevention of hemochromatosis
The treatment of hemochromatosis relies on bleeding (also called phlebotomies). They are intended to lower the level of iron in the blood and reduce iron deposits in the body without causing anemia iron deficiency.
The process is identical to that practiced during a blood donation. It is recommended to drink water after bleeding.
It is a simple treatment, inexpensive and effective, usually performed between 4 and 6 times a year, without impact on the life of the patient, especially since the bleeding can be performed at home.
The doctor defines a quantity of blood to be taken regularly from the patient taking into account his age, his weight and his size. Initially, weekly bleeding is necessary and maintained as long as iron overload is observed. When the ferritin level in the blood falls below 50 μg / L, they are performed monthly or quarterly as appropriate to maintain a ferritin level in the blood of 50 μg / L. They will be maintained for life.
This treatment does not cure the disease.
In pregnant women, bleeding is not practiced throughout pregnancy. Iron supplementation is not necessary.
Other complications of the disease (cirrhosis, heart failure or diabetes) are specifically treated.
Note that no diet can replace the bleeding treatment. The patient is advised to follow a normal diet and to limit the consumption of alcohol.
Benefits of treatment
Due to the treatment, fatigue often seen in patients with hemochromatosis fades. Above all, when the treatment is set up early, it avoids serious complications of the disease (heart, liver and pancreas) and thus lengthens the life expectancy of patients
No change in the habits of patients is to be considered in hemochromatosis apart from rules of lifestyle that include a normal diet and a decrease in alcoholic beverages if excesses were previously practiced.
Patient follow-up is provided in the hepatogastroenterology departments. In people at risk, a genetic consultation is very appropriate to detect the disease early and take the necessary therapeutic measures.