Fanconi disease or anemia is a rare genetic disease – fewer than 400 cases in France – which results in malformations and insufficient bone marrow production.
Fanconi disease is a genetic disease of the bone marrow relatively rare (300 to 400 cases in France) which was first described in 1927 by a Swiss pediatrician. Interview with Professor Régis Peffault de Latour, hematologist at Saint-Louis hospital, specialized in rare immuno-hematological diseases and coordinator of the reference center for aplastic anemia.
What is Fanconi disease?
Fanconi disease is a form of bone marrow aplasia which results in the disappearance of cells in the bone marrow. There are two types of bone marrow aplasia:
► In 80% of cases, bone marrow suppression is autoimmunethat is to say that the immune system begins to destroy the bone marrow without knowing why.
► In 20% of cases, bone marrow aplasia is due to a constitutional genetic anomaly (transmitted from parents to child). Fanconi disease is the most common of these.
What life expectancy?
“Life expectancy has improved considerably in recent decades because transplants have less toxicity than before, but usually half of patients die before the age of 40.“, indicates Professor Régis Peffault de Latour.
What are the symptoms ?
Fanconi disease results in several types of symptoms, which do not appear systematically in all individuals. The most common signs are:
► Congenital malformations: short stature, microcephaly, abnormalities of the thumbs and radii are among the physical signs most often observed. Malformations can also affect kidneys (often affected children have only one kidney), the genitals, the nervous and digestive systems, or the heart.
► Insufficiency of bone marrow. Marrow insufficiency appears later, around the age of 7 or 8, and can concern red blood cells (anemia), white blood cells (neutropenia) and platelets (thrombocytopenia). It generally progresses towards bone marrow aplasia. This insufficiency results in:
- great fatigue
- shortness of breath
- repeated infections and hematomas (due to low platelet count).
► A high risk of cancer and leukemia in patients with Fanconi disease. “As it is a DNA repair defect, affected patients can develop cancers, especially mucosal squamous cell (cancer of the mouth, esophagus) whose prognosis is not good because treatments due to the DNA repair abnormality are more toxic than beneficial“, develops the specialist.
What is the cause ?
“Fanconi disease is caused to a DNA repair abnormality. Children are born with bone marrow that is less rich than normal and becomes thinner over time. Before the age of 20, they develop one or more cytopenias which results in a decrease in blood cells, notably platelets, red blood cells and white blood cells).“, informs the hematologist.
The diagnosis of Fanconi disease is often late : it is rarely mentioned before the appearance of marrow failure called bone marrow failure. It is carried out using a chromosomal breakage test, carried out in the laboratory. A prenatal diagnosis is also possible for families who request it: by molecular analysis in families where the disease has already been studied.
Bone marrow transplantation is the only way to treat bone marrow failure.
Fanconi disease is one of the pathologies for which there is no curative treatment. Treatment therefore depends on the symptoms observed: surgery for thumb deformitieshearing, dermatological, gastrological, and/or nephrological follow-ups prescribed according to the manifestations of the disease. Bone marrow transplant is the only way to treat bone marrow failure. Regular follow-up and examinations (hemogram and myelogram) are also necessary to prevent abnormalities and the risk of leukemia. “Suspensive treatment, that is to say which makes it possible to improve things, can be proposed when the transplant is too risky: the administration of androgens. This treatment helps limit the decrease in blood cells. But the side effects of androgens are not negligible: they are virilizing so they increase hair growth and in the longer term, can cause liver tumors.specifies our expert.