Congenital dyserythropoietic anemia (CDA) is a rare blood disorder, similar to the
thalassemia
Thalassemias are inherited blood disorders characterized by decreased hemoglobin production. Symptoms depend on the type and can vary from none to severe. Often there is mild to severe anemia (low red blood cells or hemoglobin). Anemia can result ...
s. CDA is one of many types of
anemia
Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...
, characterized by
ineffective erythropoiesis Ineffective erythropoiesis is active erythropoiesis with premature death of red blood cells, a decreased output of red blood cells, RBCs from the bone marrow, and, consequently, anemia.
It is a condition characterised by the presence or abundance of ...
, and resulting from a decrease in the number of
red blood cells
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek language, Greek ''erythros'' for "red" and ''k ...
(RBCs) in the body and a less than normal quantity of hemoglobin in the blood.
[ CDA may be transmitted by both parents autosomal recessively or dominantly.
]
Signs and symptoms
The symptoms and signs of congenital dyserythropoietic anemia are consistent with:
* Tiredness (fatigue)
* Weakness
Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...
* Pale skin
Types
Congenital dyserythropoietic anemia has four different subtypes, CDA Type I, CDA Type II, CDA Type III, and CDA Type IV. CDA type II (CDA II) is the most frequent type of congenital dyserythropoietic anemias.
Diagnosis
The diagnosis of congenital dyserythropoietic anemia can be done via sequence analysis of the entire coding region
The coding region of a gene, also known as the coding sequence (CDS), is the portion of a gene's DNA or RNA that codes for protein. Studying the length, composition, regulation, splicing, structures, and functions of coding regions compared to no ...
, types I, II, III and IV ( is a relatively new form of CDA that had been found, just 4 cases have been reported[) according to the genetic testing registry.
]
Treatment
Treatment of individuals with CDA usually consist of frequent blood transfusion
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mo ...
s, but this can vary depending on the type that the individual has. Patients report going every 2–3 weeks for blood transfusions. In addition, they must undertake chelation therapy
Chelation therapy is a medical procedure that involves the administration of Chelation, chelating agents to remove heavy metals from the body. Chelation therapy has a long history of use in clinical toxicology and remains in use for some very sp ...
to survive; either deferoxamine
Deferoxamine (DFOA), also known as desferrioxamine and sold under the brand name Desferal, is a medication that binds iron and aluminium. It is specifically used in iron overdose, hemochromatosis either due to multiple blood transfusions or an un ...
, deferasirox
Deferasirox, sold under the brand name Exjade & Asunra (in injectable form) & Oleptiss (Tablet formulation) both by Novartis among others, is an oral iron chelator. Its main use is to reduce chronic iron overload in patients who are receiving l ...
, or deferiprone
Deferiprone, sold under the brand name Ferriprox among others, is a medication that chelates iron and is used to treat iron overload in thalassaemia major. It was first approved and indicated for use in treating thalassaemia major in 1994 and h ...
to eliminate the excess iron that accumulates. Removal of the spleen and gallbladder[ are common. Hemoglobin levels can run anywhere between 8.0 g/dl and 11.0 g/dl in untransfused patients, the amount of blood received by the patient is not as important as their baseline pre-transfusion hemoglobin level. This is true for ferritin levels and iron levels in the organs as well, it is important for patients to go regularly for transfusions in order to maximize good health, normal ferritin levels run anywhere between 24 and 336 ng/ml, hematologists generally do not begin chelation therapy until ferritin levels reach at least 1000 ng/ml. It is more important to check iron levels in the organs through MRI scans, however, than to simply get regular blood tests to check ferritin levels, which only show a trend, and do not reflect actual organ iron content.][
]
Gene therapy
Gene therapy
Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. The first attempt at modifying human DN ...
, as well as, bone marrow transplant
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce ...
are also possible treatments for the disorder, but each have their own risks at this point in time. Bone marrow transplantation is the more used method between the two, whereas researchers are still trying to definitively establish the results of gene therapy treatment. It generally requires a 10/10 HLA matched donor, however, who is usually a sibling. As most patients do not have this, they must rely on gene therapy research to potentially provide them with an alternative. CDA at both clinical and genetic aspects are part of a heterogeneous group of genetic conditions. Gene therapy is still experimental and has largely only been tested in animal models until now. This type of therapy has promise, however, as it allows for the autologous transplantation of the patient's own healthy stem cells rather than requiring an outside donor, thereby bypassing any potential for graft vs. host disease (GVHD).
In the United States, the FDA approved clinical trials on Beta thalassemia patients in 2012. The first study, which took place in July 2012, recruited human subjects with thalassemia
Thalassemias are inherited blood disorders characterized by decreased hemoglobin production. Symptoms depend on the type and can vary from none to severe. Often there is mild to severe anemia (low red blood cells or hemoglobin). Anemia can result ...
major,
See also
* Thalassemia
Thalassemias are inherited blood disorders characterized by decreased hemoglobin production. Symptoms depend on the type and can vary from none to severe. Often there is mild to severe anemia (low red blood cells or hemoglobin). Anemia can result ...
* Hemoglobinopathy
* List of hematologic conditions
:''This is an incomplete list, which may never be able to satisfy certain standards for completion.''
There are many conditions of or affecting the human hematologic system—the biological system that includes plasma, platelets, leukocytes, an ...
References
Further reading
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External links
{{Diseases of RBCs
Genetic disorders with no OMIM
Red blood cell disorders
Anemias