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Congenital dyserythropoietic anemia type 2



Other Names:
CDAN2; Anemia, dyserythropoietic, congenital type 2; CDA II; CDAN2; Anemia, dyserythropoietic, congenital type 2; CDA II; Dyserythropoietic anemia, HEMPAS type; HEMPAS anemia; Hereditary Erythroblastic Multinuclearity with Positive Acidified-Serum test; CDA type II; Congenital dyserythropoietic anemia type II; Hereditary erythroblastic multinuclearity with a positive acidified-serum test (hempas); SEC23B-CDG See More
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Congenital dyserythropoietic anemia type 2 (CDA II) is an inherited blood disorder characterized by mild to severe anemia. It is usually diagnosed in adolescence or early adulthood. Many affected individuals have yellowing of the skin and eyes (jaundice) and an enlarged liver and spleen (hepatosplenomegaly) and gallstones. This condition also causes the body to absorb too much iron, which builds up and can damage tissues and organs. In particular, iron overload can lead to an abnormal heart rhythm (arrhythmia), congestive heart failure, diabetes, and chronic liver disease (cirrhosis). Rarely, people with CDA type II have mediastinal tumors. CDA type II usually results from mutations in the SEC23B gene. It is inherited in an autosomal recessive pattern. Treatment depends on the severity of the symptoms and may involve blood transfusions, iron chelation therapy and removal of the spleen and gallbladder.[1][2]
Last updated: 2/12/2014

The signs and symptoms of CDA II include jaundice, gallstones and an enlarged liver and spleen. This condition also causes the body to absorb too much iron, which builds up and can damage tissues and organs. In particular, iron overload can lead to an abnormal heart rhythm (arrhythmia), congestive heart failure, diabetes, and chronic liver disease (cirrhosis). Rarely, people with CDA type II have mediastinal tumors. During pregnancy and other special circumstances (such as anemic crisis, major surgery and infections), blood transfusions may be necessary.[1][2]
Last updated: 2/12/2014

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Anemia of inadequate production 0010972
Autosomal recessive inheritance 0000007
Cholelithiasis
Gallstones
0001081
Endopolyploidy on chromosome studies of bone marrow 0003352
Jaundice
Yellow skin
Yellowing of the skin
[ more ]
0000952
Reduced level of N-acetylglucosaminyltransferase II 0003655
Reticulocytosis
Increased immature red blood cells
Increased number of immature red blood cells
[ more ]
0001923
Splenomegaly
Increased spleen size
0001744
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Last updated: 7/1/2020

The goal of CDA type 2 treatment is to address and prevent complications from anemia and iron overload.[3] Most people with CDA type 2 develop iron overload, for some this is as early as in their 20's.[3]  If a person with CDA type 2 has mild anemia, but evidence of iron loading, treatment may involve phlebotomy.[3] An alternative treatment is chelation therapy.[3][4] In particular, chelation therapy is preferred for people with iron (ferritin) levels greater than 1000 mg/L.[3] The Iron Disorders Institute provides information on chelation therapy through their Web site at:
http://www.irondisorders.org/chelation-therapy

Many people with CDA-2 maintain hemoglobin levels just above the threshold for symptoms.[4] Mild anemia may not need treatment, as long as it doesn't worsen.  Less commonly CDA-2 causes severe anemia. Treatment of severe anemia may involve blood transfusions. Blood transfusions can raise iron levels so, careful monitoring and treatment for iron overload is required.

The National Heart, Lung, and Blood Institute offers tips for living with hemolytic anemia at the following link:
http://www.nhlbi.nih.gov/health/health-topics/topics/ha/livingwith

Splenectomy is considered for people with CDA-2 and severe anemia. Splenectomy can cause a consistent rise in hemoglobin values.[3] The spleen, however, is important in fighting infection.  People, particularly children, who have had a splenectomy are more likely to contract a serious and possibly life-threatening infection (sepsis). This risk must be carefully weighed. Splenectomy does not affect iron overload.

Lastly, people with very severe CDA-2 may be candidates for hematopoietic stem cell transplantation (HSCT). Currently this is the only available curative treatment for CDA-2.[3][4][5][6]
Last updated: 6/25/2015

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The diagnosis of CDA should be considered following exclusion of other causes of hemolytic anemias (especially hereditary spherocytosis), acquired dyserythropoiesis (myelodysplastic syndromes, acute erythroid leukemia) and microcytic anemias (thalassemias or iron deficiency anemias) (see these terms). Gilbert syndrome (see this term) and infections should be also excluded.
Visit the Orphanet disease page for more information.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Congenital dyserythropoietic anemia type 2. This website is maintained by the National Library of Medicine.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Congenital dyserythropoietic anemia type 2. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have this blood disease and was reading an article stating that if I were to have kids, I would be transfusion dependent. How else would it affect my body? Would I have increased risk of liver and heart problems? I also had a splenectomy and cholesysectomy, would that put me at a higher risk for infections and diseases? See answer



  1. Congenital dyserythropoietic anemia. Genetics Home Reference (GHR). July 2009; http://ghr.nlm.nih.gov/condition/congenital-dyserythropoietic-anemia.
  2. Fernandez, M. Congenital dyserythropoietic anemia type II. Orphanet. September 2013; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=98873.
  3. Renella R, Wood WG. The congenital dyserythropoietic anemias. Hematol Oncol Clin North Am. 2009 Apr; 23(2):283-306. Accessed 6/25/2015.
  4. Renella R. Progress in the congenital dyserythropoietic anemias: juicy but high-hanging fruits?. Am J Hematol. 2010 Dec; 85(12):913-4. Accessed 6/25/2015.
  5. Unal S. Successful hematopoietic stem cell transplantation in a patient with congenital dyserythropoietic anemia type II. Pediatr Transplant. 2014 Jun; 18(4):E130-3. Accessed 6/25/2015.
  6. Braun M. Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation. Pediatr Blood Cancer. 2014 Apr; 61(4):743-5. Accessed 6/25/2015.