Fanconi anemia
The content of the article:
- Causes and risk factors
- Symptoms
- Diagnostics
- Treatment
- Possible complications and consequences
- Forecast
- Prevention
Fanconi's anemia is a rare disease, the development of which is caused by a genetic defect in a group of proteins responsible for the repair (correction of breaks and errors) of DNA molecules. This leads to increased fragility of chromosomes, as a result of which aplastic anemia develops in patients with age and neoplastic processes are triggered.
Fanconi anemia occurs with an incidence of 1 in 350,000 newborns. A higher incidence rate is noted in South Africans and Ashkenazi Jews - 1 case in 90 newborns.
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Causes and risk factors
In most cases, Fanconi's anemia is characterized by an autosomal recessive mode of inheritance. This means that for the development of pathology, the child must receive a mutated gene from both the mother and the father. In cases where he receives only one copy of the altered gene, the disease will not develop, but the child will be the carrier of the pathological gene and will be able to pass it on to his offspring in the future. If both the father and the mother are carriers of the mutated gene, the probability of having a sick child is 25%.
There is a form of Fanconi anemia with recessive X-linked inheritance. In this case, the carriers of the mutation are women. They have a 50% chance of having a son with Fanconi anemia.
Fanconi anemia is inherited in an autosomal recessive manner - the child must receive the mutated gene from both parents
Symptoms
The first signs of hematopoiesis disorders in Fanconi anemia begin to appear in children after 6-7 years. But this pathology can be suspected earlier by the appearance of patients who are characterized by:
- short stature;
- microphthalmia;
- microcephaly;
- dark skin;
- malformed thumbs;
- the presence of hyper- and hypopigmentation areas on the skin and mucous membranes.
In addition, other anomalies may be observed:
- mental retardation;
- deafness;
- eye tremor;
- strabismus;
- ptosis of the eyelid;
- hypospadias;
- lack of testicles, underdevelopment of the genitals;
- congenital heart defects;
- polycystic or hypoplasia of the kidneys, horseshoe kidneys;
- doubling of the ureters and (or) pelvis.
With Fanconi anemia, the hematopoietic function of the bone marrow is gradually disrupted. In the first years of life, the level of blood cells usually corresponds to normal age indicators, but red blood cells are significant in size (macrocytosis). In subsequent years, patients develop pancytopenia, that is, the level of all blood cell lines decreases.
A decrease in the number of platelets causes bruising, frequent nosebleeds. As a result of a decrease in the number of red blood cells, anemia occurs with the following characteristic symptoms:
- pallor of the skin;
- weakness;
- tachycardia;
- feeling short of breath, shortness of breath.
A decrease in the number of neutrophils (neutropenia) leads to a low resistance of the body to infections.
In the future, oncological diseases often develop (in particular, leukemia and myelodysplastic syndrome).
Diagnostics
Fanconi's anemia can be suspected based on the patient's characteristic appearance and changes in the clinical blood test. The myelogram (analysis of the cellular composition of the bone marrow) allows to clarify the diagnosis.
For the final diagnosis, a cytogenetic study of blood cells is necessary (test with mitomycin C or test with diepoxybutane). In specialized laboratories, molecular genetic analysis can also be performed, which makes it possible to identify the presence of a specific genetic defect in a patient.
Treatment
The only method to achieve the restoration of hematopoiesis in Fanconi's anemia is donor bone marrow transplantation. It is advisable to implement it in the first decade of a child's life, since the effectiveness of transplantation decreases significantly at an older age. The best results are observed in cases when the patient's close relatives who do not have this disease act as bone marrow donors.
When preparing patients for bone marrow transplantation with Fanconi anemia, the following features should be taken into account: they have an increased sensitivity to the damaging effects of chemotherapy drugs and ionizing radiation, they have an increased risk of developing chronic and acute graft-versus-host reactions.
Donor bone marrow transplant is indicated for Fanconi anemia
If, for any reason, bone marrow transplantation is impossible, conservative therapy is performed to stimulate hematopoietic processes. For this purpose, drugs are prescribed for male sex hormones (androgens) or growth factors. In about 50% of cases, hormone therapy with androgens responds well, and for many years it keeps the production of blood cells in the bone marrow at the proper level. However, in the future, its effectiveness decreases, the likelihood of developing side effects increases.
In severe cases, transfusion of erythrocyte, leukocyte or platelet mass is carried out.
Possible complications and consequences
The most common complications of Fanconi anemia are:
- accession of a secondary infection;
- increased bleeding;
- the development of leukemia.
Forecast
The prognosis for Fanconi anemia is serious. Most patients live no more than 40 years. Even after successful bone marrow transplantation and restoration of the function of hematopoiesis, the likelihood of developing cancer remains very high.
Prevention
It is impossible to prevent the development of Fanconi anemia. If there are cases of this disease in the family, prenatal diagnosis is recommended for a pregnant woman: blood is taken from the umbilical cord vein of the fetus (cordocentesis), a test with diepoxybutane is put. If the result is positive, the couple is offered to terminate the pregnancy for medical reasons.
Elena Minkina Doctor anesthesiologist-resuscitator About the author
Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.
Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
