According to abbreviationfinder, CDA stands for congenital dyserythropoietic anemia. Congenital dyserythropoietic anemias (CDA) are very rare congenital diseases characterized by ineffective blood formation. The first symptoms of anemia appear in childhood. These diseases can be treated quite well with various therapeutic measures.
What is congenital dyserythropoietic anemia?
The diagnosis of CDA includes characterization of the erythrocytes and laboratory tests of various blood parameters. Typical are low hemoglobin and haptoglobin values as well as increased values for bilirubin and ferritin.
Congenital dyserythropoietic anemias belong to a group of rare blood diseases that are caused by different gene mutations. As part of these mutations, mostly immature and diseased erythrocytes are formed, which are subject to increased hemolysis.
To compensate for this haemolysis, blood formation is further boosted. Nevertheless, the anemia cannot be overcome by this. Normal erythrocytes mature in the bone marrow and then enter the bloodstream, where they have an average lifespan of about 120 days. In CDA, however, the erythrocytes in the bone marrow do not mature.
The immature erythrocytes often die off there. There are currently four sub-forms of CDA, which are based on different mutations. These are the forms type I CDAN1 to type IV CDAN4. Types I and II are the most common, with type II predominating.
However, the distinction between CDA forms is important for the choice of therapy. It is currently assumed that the frequency of the disease is very low. In Europe, two to three people per million are said to suffer from CDA.
Causes
All forms of CDA are hereditary. Depending on the severity of the disease, the first symptoms often begin shortly after birth. Sometimes they don’t appear until adulthood. Most forms of CDA are inherited in an autosomal recessive manner. This means that the disease cannot be passed directly from one generation to another.
The disease only develops when both parents transmit a defective gene to their offspring. However, since the mutated genes are very rare, CDA occurs mainly in children of related parents. Type I CDAN1 is a mutation of the CDAN1 gene, which encodes the protein codanin-1.
When this protein changes, a chromatin bridge forms between the nuclei of the still immature erythrocytes. These are small strands of protein and DNA that hold the nuclei together. At the same time, the nuclear membranes are permeable to substances from inside the cell. As a result, a disturbed nuclear metabolism develops. In the more common type II CDAN2, a gene on chromosome 20 is affected by a mutation.
Large immature erythrocytes with multiple nuclei form here. This multinuclearity causes errors in cell division. Metabolic disorders occur in the cell walls of the red blood cells. Type III CDAN3 is caused by an autosomal dominant mutation in the KIF23 gene on chromosome 15 and type IV CDAN4 by a mutation in the KLF1 gene on chromosome 19.
Symptoms, Ailments & Signs
All CDA forms are characterized by three sets of symptoms. These include hemolytic anemia, symptoms of increased blood formation and signs of iron overload. Hemolytic anemia is caused by the increased breakdown of diseased erythrocytes.
It manifests itself in rapid fatigability, increasing paleness, headaches, difficulty breathing during physical exertion, jaundice, formation of gallstones and enlargement of the spleen. Anemia can even worsen during an aplastic crisis. The formation of new erythrocytes in the bone marrow is temporarily completely interrupted by the influence of the parvovirus B19 (the pathogen that causes ringworm).
Only blood degradation takes place. However, in general, anemia provokes increased formation of erythrocytes in the bone marrow. However, since the immature erythrocytes are quickly broken down again, this process is further intensified. The unusually strong formation of new erythrocytes in the bone marrow requires more space and therefore leads to the expansion of the bones.
Finally, other organs such as the spleen can also be used to form blood, causing them to enlarge. The iron overload that causes the third symptom complex is caused by the increased blood formation activity in the bone marrow.
The ineffective formation of immature erythrocytes binds more iron, which is deposited in various organs after the blood cells have broken down. Heart muscle weakness, liver dysfunction, hypothyroidism and other metabolic disorders occur.
Diagnosis & course of disease
The diagnosis of CDA includes characterization of the erythrocytes and laboratory tests of various blood parameters. Typical are low hemoglobin and haptoglobin values as well as increased values for bilirubin and ferritin.
Complications
As a rule, this disease leads to a greatly reduced blood formation in the patient. This has a negative impact on the entire organism of the patient and can greatly reduce their resilience. Tiredness also occurs and those affected appear pale or suffer from headaches.
Difficulty breathing or jaundice can also occur, and the spleen can enlarge. This often causes pain. If these also occur at night in the form of rest pain, the patient may continue to suffer from sleep problems. Likewise, other organs can also become enlarged due to reduced blood formation, resulting in damage to the organs or other complaints.
The heart muscle may be weakened and liver or thyroid disorders may occur. The patient’s quality of life is significantly reduced by this disease. Treatment usually does not lead to complications. Blood loss can be compensated for with the help of transfusions. The spleen may also need to be removed. Life expectancy is not reduced with early and correct treatment.
When should you go to the doctor?
Parents who notice their child becoming tired and exhausted easily, possibly with headaches, breathing difficulties and other symptoms, should contact the pediatrician. Congenital dyserythropetic anemia must be treated early to rule out health complications and long-term consequences. Therefore, medical advice should be sought at the first sign of a serious illness. If the child is already showing signs of jaundice or gallstones, parents should take them to a hospital.
If there are signs of an aplastic crisis, which is manifested by paleness, exhaustion and dizziness, the emergency doctor must be called. CDA is hereditary and can be diagnosed with a genetic test. If there are cases of the disease in the family, a test should be arranged at an early stage. In this way, CDA can be recognized and treated in good time before serious complications arise. Parents can visit the pediatrician or an internist. Further treatment usually takes place in a specialist center for hereditary diseases.
Treatment & Therapy
Therapy for CDA includes regular blood transfusions, taking blood-forming substances, removing the spleen if necessary, stem cell transplants, and taking medication to remove excess iron. The administration of blood-forming substances such as alpha-interferon is suitable for type I CDAN1 CDA.
Removing the spleen can extend the lifespan of the erythrocytes. However, due to the possible complications, this operation is only performed in very severe cases. In very severe cases, a stem cell transplant can also be considered. To do this, however, the blood characteristics of the donor and recipient must essentially match.
Patients with CDA must always be given medication to counteract iron overload. Iron overload occurs both with the increased formation of erythrocytes and as a result of frequent blood transfusions. Iron chelators are used as drugs to remove excess iron.
Outlook & Forecast
Congenital dyserythropoietic anemia (CDA) is very rare. With early diagnosis and treatment, most newborns with congenital dyserythropoietic anemia have a reasonable prospect of having a normal life expectancy. However, it is important that those affected and their relatives cooperate optimally. Disturbed blood formation has consequences that last a lifetime.
If possible, treatment should be carried out by a team of specialist doctors. The cooperation of general practitioners or paediatricians with specialists in blood diseases improves the statistical chances of those affected to have a reasonably normal life. The problem, however, is that even specialists cannot make any predictions about the course of congenital dyserythropoietic anemia (CDA). Many factors can affect survival with a blood disorder.
CDA can only be cured with a stem cell transplant. For the most part, however, physicians are concerned with alleviating the symptoms and sequelae of congenital dyserythropoietic anemia. With the optimal cooperation of patient and family, a high life expectancy can be assumed, at least in countries with a high medical standard. In other countries, where such conditions do not exist, the survival prognosis looks worse. It should be noted, however, that a positive forecast can also prove to be deceptive in this country. The CDA can take an unfavorable course due to many circumstances.
Prevention
It is not possible to prevent CDA because it is a very rare hereditary disease. The corresponding mutations are also usually inherited in an autosomal recessive manner. Therefore, there is only an increased risk of this disease in descendants of relatives.
Aftercare
With this disease, the measures and options for aftercare are significantly limited in most cases. First and foremost, the disease should be recognized by a doctor at an early stage so that the symptoms do not get worse. If you want to have children, genetic counseling can also be useful to prevent the disease from recurring in the children.
Self-healing will not usually occur. The treatment itself is carried out by taking various medications, whereby the person concerned should ensure that they are taken regularly and that the medication is dosed correctly. If anything is unclear or if you have any questions, always consult a doctor first.
Regular blood transfusions are also necessary, so that many patients are dependent on the help and care of family, friends and acquaintances in their lives due to the disease. Loving conversations also have a positive effect on the further course of the disease, since in many cases depression and other mental upsets can be prevented. The disease may also reduce the life expectancy of those affected.
You can do that yourself
Patients with congenital dyserythropoietic anemia are able to improve their quality of life through certain measures and contribute to the success of the therapy. Those affected suffer from reduced performance and tire quickly. Accordingly, the patients refrain from mentally overloading themselves. Instead, the sick people, together with the doctor and physiotherapist, choose sports and exercises that are appropriate to the ability of the sick person. This means that there is no overload and the patients still train their muscles and condition.
Those affected regularly visit the doctor for various examinations and therapeutic measures. Hospital stays may be necessary, for example if the spleen has to be removed due to enlargement. Nursing staff and doctors provide important instructions on how to rest, take medication, and diet to be followed by the patient.
With adequate treatment of the disease, patients are able to participate in social life and attend a normal school. However, it is possible that the affected children do not participate in physical education classes. For appropriate patient care, it is important that the social environment is informed about the existence of the disease and intervenes in the event of medical complications.
