Congenital dyserythropoietic anemia type II (CDA II), or hereditary erythroblastic multinuclearity with positive acidified serum lysis test (HEMPAS)
is a rare genetic anemia in humans characterized by hereditary erythroblastic multinuclearity with positive
acidified serum lysis
The Ham test is a blood test used in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). Patient red blood cells (RBCs) are placed in mild acid; a positive result (increased RBC fragility) indicates PNH or congenital dyserythropoietic anemi ...
test.
Presentation
Genetics
CDA type II is caused by mutations in the SEC23B gene. This gene provides instructions for making a protein that is involved in the transport of other proteins within cells. During the development of red blood cells, this protein may help ensure that proteins are transported to the areas where they are needed. Researchers are working to determine how mutations in the SEC23B gene lead to the signs and symptoms of CDA type II.
Analyses of CDA II erythrocyte membranes showed that the band 3 glycoprotein is underglycosylated. An aberrant glycosylation pattern is seen in the polylactosamine carbohydrates which are normally attached to the band 3 and band 4.5 glycoproteins. The polylactosamines are, however, accumulated in the form of glycolipids. Therefore a genetic factor in CDA II appears to block the glycosylation of protein acceptors and shift these carbohydrates to the lipid acceptors. Structural analysis of CDA II band 3 carbohydrates identified truncated hybrid-type oligosaccharides and suggests that the Golgi glycosylation enzyme(s), alpha-mannosidase II or N-acetylglycosaminyltransferase II is defective in CDA II.
[
]
Diagnosis
The anemia associated with CDA type II can range from mild to severe, and most affected individuals have jaundice, hepatosplenomegaly, and the formation of hard deposits in the gallbladder called bilirubin gallstones. This form of the disorder is usually diagnosed in adolescence or early adulthood. An abnormal buildup of iron typically occurs after age 20, leading to complications including heart disease, diabetes, and cirrhosis.
Treatment
Treatment consists of frequent blood transfusions and 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 ...
. Potential cures include bone marrow transplantation and 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 ...
.
See also
* Congenital dyserythropoietic anemia
Congenital dyserythropoietic anemia (CDA) is a rare blood disorder, similar to the thalassemias. CDA is one of many types of anemia, characterized by ineffective erythropoiesis, and resulting from a decrease in the number of red blood cells (RBCs) ...
* 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
Hemoglobinopathy is the medical term for a group of inherited blood disorders and diseases that primarily affect red blood cells. They are single-gene disorders and, in most cases, they are inherited as autosomal co-dominant traits.
There are tw ...
* 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
*
*
Congenital dyserythropoietic anemia
at the US National Institutes of Health
The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...
Home Genetic Reference
External links
{{Medical resources
, ICD10 = D64.4
, ICD9 = {{ICD9, 285.8
Genetic disorders with no OMIM
Anemias