Congenital dyserythropoietic anemia, type III, also called CDA type III, is a very rare inherited blood disease. In this disease, the bone marrow tries to make red blood cells, but many developing red blood cells grow in an abnormal way. Because of this, the body cannot make enough healthy red blood cells. This causes anemia. The most important bone marrow sign is the presence of very large erythroblasts with more than one nucleus, sometimes called giant multinucleated erythroblasts or gigantoblasts. The disorder is part of the larger group called congenital dyserythropoietic anemias, which are genetic disorders of red blood cell production. 1 2 3
Congenital dyserythropoietic anemia type III, or CDA type III, is a very rare inherited blood disease. In this condition, the bone marrow makes red blood cells in an abnormal way, so many young red blood cells do not mature well. This causes anemia, which means the body has fewer working red blood cells to carry oxygen. CDA type III is linked mainly to changes in the KIF23 gene or RACGAP1 gene. A classic finding is very large multinucleated erythroblasts in the bone marrow. The illness can be mild in some people and more serious in others. Some families also have eye problems or later blood complications, so long-term follow-up is important. [1]
Congenital means the problem is present from birth, even if it is not found at birth. Dyserythropoietic means “abnormal red blood cell production.” Anemia means there are too few healthy red blood cells or too little hemoglobin to carry oxygen well. In CDA type III, the main problem starts inside the marrow during red blood cell development. The cells do not divide in the normal way. This leads to ineffective erythropoiesis, which means the marrow is active but still does not produce enough normal mature red cells. 2 3 4
Another names
Congenital dyserythropoietic anemia, type III is also called CDA III, CDA type 3, type III congenital dyserythropoietic anemia, and in older family reports it was linked with familial erythroid multinuclearity. Some experts also describe two forms: CDA IIIa for the usual autosomal dominant form linked to KIF23, and CDA IIIb for the autosomal recessive form linked to RACGAP1. 1 2 3
Types
- Autosomal dominant CDA IIIa. This is the classic family form. It is most strongly linked to changes in the KIF23 gene. It may be mild to moderate, but some families also show eye changes such as angioid streaks and a higher risk of monoclonal gammopathy or multiple myeloma. 1 4 5
- Autosomal recessive CDA IIIb. This form is linked to RACGAP1 changes. It can show macrocytic anemia, marked dyserythropoiesis, giant multinucleated erythroblasts, and sometimes liver or spleen enlargement. Both parents may carry one changed copy of the gene but may not have anemia themselves. 1 3 6
Causes
This disease does not have 20 completely separate proven root causes like an infection. The main proven causes are gene changes in KIF23 or RACGAP1. To match your request clearly and honestly, the 20 items below are cause-related genetic and disease mechanisms that explain why CDA type III happens or why the anemia appears. 1 2
- KIF23 gene mutation. This is a proven direct cause of the dominant form of CDA III. 1 4
- RACGAP1 gene mutation. This is a proven direct cause of the recessive form of CDA III. 1 3
- Autosomal dominant inheritance. One changed copy of the disease gene can be enough to cause illness in some families. 1 4
- Autosomal recessive inheritance. Two changed copies can cause disease in the RACGAP1 form. 1 3
- Abnormal cytokinesis. The red cell precursors fail to separate properly when they divide. This is a central disease mechanism. 3 4
- Centralspindlin dysfunction. KIF23 and RACGAP1 both work in the centralspindlin complex. Damage to this system leads to abnormal cell division. 3 4
- Failure of erythroblast maturation. Developing red blood cells do not mature in the normal step-by-step way. 2 3
- Ineffective erythropoiesis. The marrow makes many erythroid cells, but many are destroyed or fail before becoming useful mature red cells. 2 6
- Multinuclearity of erythroblasts. The abnormal division creates cells with more than one nucleus, which is a key part of disease formation. 1 3
- Gigantoblast formation. Very large erythroblasts appear in bone marrow because normal cell division is disturbed. 1 3
- Macrocytic red cell production. In some patients the red cells are larger than normal, showing disturbed red cell development. 1 3
- Megaloblastoid erythroid change. The marrow cells may look megaloblast-like because of abnormal maturation. 3 6
- Erythroid hyperplasia. The marrow expands the red cell line to compensate, but the effort is not efficient. 1 5
- Chronic hemolytic component. Some abnormal red cells break down early, adding to the anemia. 2 5
- Iron overabsorption from ineffective erythropoiesis. The body may absorb too much iron over time, which can worsen complications. 2 6
- Family history of CDA III. A positive family history raises suspicion because this is often inherited. 1 4
- Rare sporadic presentation with hidden recessive variants. Some patients have no family history because each parent is an unaffected carrier. 3 6
- Defective Rho-family signaling through RACGAP1 dysfunction. This abnormal signaling contributes to failed cytokinesis in erythroid cells. 3
- Defective MKLP1 function from KIF23 mutation. MKLP1 is needed for daughter cell separation, and its dysfunction drives the dominant form. 4 7
- Inherited marrow cell production disorder present from birth. This is not caused by poor diet, germs, or injury. It is a built-in genetic disease of red cell production. 1 2
Symptoms
- Tiredness happens because the blood carries less oxygen when anemia is present. 2 5
- Weakness is common for the same reason. The muscles and brain receive less oxygen-rich blood. 2
- Pale skin can appear because hemoglobin is low. 2 6
- Shortness of breath on activity may happen when the body tries to make up for anemia. 2
- Fast heartbeat can occur because the heart pumps harder to deliver oxygen. 2
- Jaundice means yellow eyes or skin. It can happen when red cells break down and bilirubin rises. 2 5
- Dark urine may happen if hemolysis is present and hemoglobin breakdown products rise. 6
- Enlarged spleen may appear because the spleen removes abnormal red cells. 2 6
- Enlarged liver can occur in some patients, especially when the marrow and blood system are under stress. 6
- Abdominal fullness or swelling may be felt when the spleen or liver is enlarged. 6
- Gallstones may develop over time in chronic hemolytic states. 2
- Poor exercise tolerance may happen even when the anemia is only mild. 2 5
- Vision problems can happen in some dominant families because retinal angioid streaks may develop. 1 5
- Symptoms from iron overload may appear later, such as liver problems, endocrine problems, or worsening fatigue, especially after years of disease. 2 6
- Few or no symptoms in mild cases is also important. Some patients adapt well and may have only mild anemia for many years. 5 1
Diagnostic tests
Physical exam tests
- General physical examination checks pallor, tired appearance, jaundice, growth, and overall health. It helps the doctor suspect chronic anemia. 2
- Skin and eye examination for jaundice looks for yellow color from bilirubin increase caused by red cell breakdown. 2
- Abdominal examination for spleen enlargement helps find splenomegaly, which is common in chronic red cell disorders. 2 6
- Abdominal examination for liver enlargement helps detect hepatomegaly, which can occur in some cases. 6
Manual tests
- Detailed family history is very important because CDA III may follow dominant or recessive inheritance patterns. 1 3
- Clinical history of anemia symptoms since childhood helps separate a congenital disorder from a new acquired anemia. 2
- Peripheral blood smear review by microscope is a manual laboratory examination that looks at red cell size and shape and supports the diagnosis of dyserythropoiesis. 2 6
- Bone marrow aspirate morphology is one of the most important tests. The pathologist looks for giant multinucleated erythroblasts and dyserythropoiesis. 1 3
- Bone marrow biopsy helps show erythroid hyperplasia and the full marrow picture when aspirate findings need confirmation. 3 5
Lab and pathological tests
- Complete blood count or CBC measures hemoglobin, red cell number, and mean cell volume. It often shows anemia and may show macrocytosis. 1 3
- Reticulocyte count helps judge marrow response. In CDA, the reticulocyte response may be less than expected for the degree of anemia. 2
- Bilirubin test checks especially indirect bilirubin, which may rise when red cells break down. 2
- Lactate dehydrogenase or LDH may be high because of hemolysis and ineffective erythropoiesis. 2
- Haptoglobin may be low when hemolysis is present, so it helps support red cell breakdown. 2
- Iron studies such as ferritin and transferrin saturation are used because CDA patients can absorb excess iron over time. 2
- Vitamin B12 and folate tests are used to rule out other common causes of macrocytic anemia before calling it CDA III. 3
- Direct antiglobulin test or Coombs test may be done to rule out autoimmune hemolytic anemia, which can look similar. 3
- Genetic testing for KIF23 and RACGAP1 is a key confirmatory test. Finding a disease-causing variant strongly supports the diagnosis and helps with family counseling. 1 3 8
Electrodiagnostic tests
- Electrodiagnostic tests are not routine for CDA III because this is a blood disease, not a nerve or muscle disease. They are only used if another problem is suspected. This honest point is important in evidence-based diagnosis. 1 2
Imaging tests
- Ultrasound or other imaging of the abdomen can check spleen size, liver size, gallstones, and organ changes from chronic anemia or iron overload. Eye examination with retinal imaging may also be useful in families at risk for angioid streaks. 1 2 5
Non-pharmacological treatments and supportive therapies.
1) Regular hematology follow-up. This is one of the most important treatments because CDA type III can change slowly over time. Regular visits help doctors check hemoglobin, reticulocyte count, bilirubin, ferritin, liver function, and symptoms like tiredness or shortness of breath. The purpose is early detection of worsening anemia or iron overload. The mechanism is simple: frequent review lets problems be found before they damage the liver, heart, spleen, or eyes. [3]
2) Genetic counseling. Since CDA type III is inherited, families benefit from genetic counseling. This helps people understand the cause, inheritance pattern, family risk, testing options, and pregnancy planning. The purpose is informed decision-making. The mechanism is education plus family screening, which may identify affected relatives earlier and reduce delayed diagnosis. [4]
3) Red blood cell transfusion planning. Some people with CDA type III do not need regular transfusions, while others may need them during severe anemia, infection, surgery, pregnancy, or growth periods. The purpose is to raise oxygen-carrying capacity fast. The mechanism is direct replacement of missing or poorly functioning red blood cells. Transfusions help symptoms, but repeated transfusions can increase body iron. [5]
4) MRI-based iron monitoring. Iron can build up in the body from transfusions and also from increased absorption in chronic ineffective erythropoiesis. MRI of the liver, and sometimes the heart, helps measure iron noninvasively. The purpose is to find iron overload before organ injury develops. The mechanism is early measurement, which guides when chelation is needed. [6]
5) Bone marrow evaluation when diagnosis is unclear. Bone marrow examination is not needed all the time, but it is important when doctors need to confirm the disease or rule out another marrow disorder. The purpose is accurate diagnosis. The mechanism is direct study of erythroblasts, especially the large multinucleated forms typical of CDA III. [7]
6) Eye examination. Some forms of CDA type III have been linked with retinal or macular problems. The purpose is to protect vision and detect eye complications early. The mechanism is routine retinal monitoring, which can find changes before major visual loss happens. [8]
7) Screening for monoclonal gammopathy or myeloma risk in adulthood. Some reported cases of CDA type III have later developed monoclonal gammopathy or multiple myeloma. The purpose is early cancer detection in adults with concerning symptoms or family history. The mechanism is periodic blood testing and specialist review when clinically needed. [9]
8) Energy pacing and fatigue management. Anemia often causes tiredness, weak exercise tolerance, and poor concentration. The purpose is to reduce symptoms without overloading the body. The mechanism is balancing activity with rest, avoiding heavy exertion during low-hemoglobin periods, and protecting oxygen demand. [10]
9) Good hydration. Good fluid intake does not cure CDA type III, but it supports circulation and general health, especially during fever, vomiting, heat exposure, or transfusion periods. The purpose is to reduce stress on the body. The mechanism is maintaining blood volume and tissue perfusion. [11]
10) Infection prevention. Viral or bacterial illness can worsen anemia or trigger clinical decline. The purpose is to lower extra stress on the marrow. The mechanism is vaccination, hand hygiene, dental care, quick treatment of fever, and avoiding exposure to contagious illness when possible. [12]
11) Transfusion safety matching. In people who need repeated transfusions, extended blood matching can reduce some transfusion reactions and alloimmunization. The purpose is safer long-term support. The mechanism is closer donor-recipient matching. [13]
12) Pregnancy planning with specialists. Pregnancy can worsen anemia in some inherited blood disorders. The purpose is safer maternal and fetal care. The mechanism is checking hemoglobin, iron, transfusion needs, and genetic counseling before and during pregnancy. [14]
13) Nutrition review by a dietitian. Food cannot cure CDA type III, but nutrition affects strength, recovery, and deficiency states that may worsen anemia. The purpose is supportive health. The mechanism is correcting low folate, B12, protein, or calorie intake while avoiding unnecessary iron loading. [15]
14) Avoiding unnecessary iron supplements. Many anemia patients are given iron automatically, but this can be harmful if the real problem is CDA with iron loading. The purpose is to prevent extra iron accumulation. The mechanism is giving iron only when proven deficiency exists. [16]
15) Liver protection. Iron overload can damage the liver. The purpose is to reduce added liver stress. The mechanism is limiting alcohol, avoiding unnecessary hepatotoxic drugs, and monitoring liver tests closely. [17]
16) Heart monitoring in significant iron overload. Severe iron overload can affect the heart. The purpose is to catch rhythm or pump problems early. The mechanism is ECG, echocardiography, or cardiac iron imaging when indicated. [18]
17) Gallbladder assessment if hemolysis symptoms appear. Chronic red cell turnover can contribute to bilirubin-related problems in inherited anemias. The purpose is to detect gallstones or biliary pain. The mechanism is ultrasound and symptom review. [19]
18) Psychological support. Living with a rare lifelong disease can cause stress, fear, and treatment fatigue. The purpose is mental well-being and better adherence. The mechanism is counseling, family support, and practical education. [20]
19) School or work adjustment. Some patients need lighter physical demands or more rest during anemia flares. The purpose is daily function. The mechanism is reducing oxygen demand while maintaining participation in life. [21]
20) Stem cell transplant evaluation only in exceptional severe cases. This is not routine for most CDA III patients, but in severe transfusion-dependent inherited marrow disorders, transplant may be discussed by experts. The purpose is possible long-term cure in selected cases. The mechanism is replacing diseased hematopoiesis with donor stem cells, but risk is high, so specialist judgment is essential. [22]
20 drug treatments or supportive medicines. Because CDA type III has no specific FDA-approved drug, the medicines below are supportive options doctors may use only when clinically appropriate.
1) Deferasirox. This oral iron chelator is FDA-approved for chronic transfusional iron overload. It is used when iron builds up from repeated transfusions or heavy iron burden. A common starting dose in labeling has been 20 mg/kg once daily for transfusional overload, with adjustments by iron burden and response. Purpose: remove extra iron. Mechanism: binds iron so the body can excrete it. Main risks include kidney injury, liver injury, and gastrointestinal bleeding. [23]
2) Deferoxamine. This is an injectable iron chelator used for chronic iron overload. Purpose: lower body iron when overload threatens the liver, heart, or endocrine organs. Mechanism: it binds free iron and helps removal in urine and stool. It is often given by subcutaneous or intravenous infusion under specialist care. Main risks include visual or hearing problems, local reactions, allergy, and infection concerns. [24]
3) Deferiprone. This oral chelator is FDA-approved for transfusional iron overload in selected settings. Purpose: reduce iron when other chelators are unsuitable or inadequate. Mechanism: it binds iron for urinary excretion. Labeling warns strongly about agranulocytosis and neutropenia, so blood count monitoring is critical. Typical labeled adult dosing is divided into three daily doses, individualized by the prescriber. [25]
4) Epoetin alfa. This erythropoiesis-stimulating agent is not specifically approved for CDA III, but doctors may sometimes consider it in special anemia situations. Purpose: support red cell production. Mechanism: acts like erythropoietin to stimulate marrow erythroid cells. Dosing varies by indication and patient context. Important risks include high blood pressure, thrombosis, stroke, and cardiovascular events when hemoglobin is pushed too high. [26]
5) Darbepoetin alfa. This is another erythropoiesis-stimulating agent with a longer action than epoetin alfa. Purpose: increase hemoglobin in selected anemia settings under specialist supervision. Mechanism: stimulates erythropoiesis through erythropoietin receptors. Dosing schedule is less frequent than epoetin in approved uses, but it must be individualized. Risks include thrombosis, hypertension, stroke, and cardiovascular harm. [27]
6) Folic acid. Folic acid does not cure CDA III, but it may be given when folate need is increased or folate deficiency is present, because chronic red cell turnover can increase folate use. Purpose: support DNA synthesis in red cell production. Mechanism: replaces folate needed for cell division. Usual clinical doses vary, and high doses should not be used blindly because folate can mask B12 deficiency. [28]
7) Cyanocobalamin. Vitamin B12 treatment is used only if B12 deficiency is present. Purpose: correct another cause of anemia that can worsen symptoms. Mechanism: restores B12 needed for normal blood cell production and nerve function. Dosing depends on route and severity; injectable forms commonly contain 1000 mcg/mL in FDA labeling. Main caution: do not assume every anemia is B12 deficiency. [29]
8) Acetaminophen before or after transfusion if needed. This is not a disease-specific treatment, but it is sometimes used for comfort around transfusion or fever management when a doctor advises it. Purpose: reduce pain or fever. Mechanism: central antipyretic and analgesic effect. It does not treat the anemia itself. [30]
9) Antihistamines for mild transfusion reactions when prescribed. In selected patients, clinicians may use antihistamines if there is itching or a mild allergic transfusion reaction. Purpose: symptom control. Mechanism: blocks histamine response. This is supportive only and should never replace proper transfusion evaluation. [31]
10) Antibiotics for proven infection. Antibiotics do not treat CDA III itself, but infection can worsen anemia and raise treatment needs. Purpose: treat bacterial infection quickly. Mechanism: kill or inhibit bacteria. The exact drug depends on the infection site, culture result, and age of the patient. [32]
11) Antiviral treatment when indicated. Viral infections can worsen marrow stress. Purpose: treat specific confirmed viral disease. Mechanism: virus-specific inhibition. These medicines are only used when there is a clear infection and a medical reason. [33]
12) Calcium and vitamin D support during long-term illness care. These are supportive rather than disease-specific. Purpose: protect bone health, especially in patients with chronic disease, low sun exposure, or reduced activity. Mechanism: support bone mineralization. They do not correct the genetic cause of CDA III. [34]
13) Antiemetics during chelation if nausea occurs. Some iron chelators can upset the stomach. Purpose: improve treatment tolerance. Mechanism: reduce nausea pathways. Choice depends on the patient and should be guided by a clinician. [35]
14) Proton pump inhibitor only when a doctor decides it is needed. In patients with medicine-related upper gastrointestinal symptoms, a doctor may choose stomach-protective treatment. Purpose: reduce acid-related symptoms. Mechanism: lowers gastric acid. This is symptom care, not CDA-specific therapy. [36]
15) Vaccines as preventive biologic treatment. Vaccines are not curative, but they are important supportive care, especially if splenectomy is ever planned. Purpose: reduce severe infection risk. Mechanism: train the immune system before exposure. [37]
16) Iron therapy only if real iron deficiency is proven. Some patients with anemia may also have a true iron deficiency from another cause. Purpose: correct documented deficiency. Mechanism: replace missing iron for hemoglobin synthesis. But in CDA with iron overload tendency, routine iron use can be harmful. [38]
17) Bile acid or gallstone-related medicines when complications occur. These are complication-directed treatments in selected patients with biliary disease. Purpose: manage gallbladder symptoms. Mechanism depends on the exact medicine. This is not routine for all patients. [39]
18) Pain medicines after procedures or during complications. Purpose: comfort and function. Mechanism: analgesia. These drugs should be chosen carefully because some can affect the stomach, kidneys, or bleeding risk. [40]
19) Hormone replacement if iron overload causes endocrine damage. In severe iron overload, some patients may later need thyroid, sex hormone, or diabetes treatment. Purpose: correct organ failure from iron injury. Mechanism: replace missing hormone function. This is complication care, not direct CDA therapy. [41]
20) Specialist transplant medicines in rare severe cases. If a patient undergoes stem cell transplantation, many medicines are used for conditioning, infection prevention, and graft support. These are advanced hospital treatments, not standard CDA III drugs. Their use depends completely on transplant team protocols. [42]
Dietary molecular supplements.
These are not proven cures for CDA type III, but doctors may use them when a deficiency or special need exists.
1) Folic acid supplement supports red cell DNA synthesis.
2) Vitamin B12 supports normal blood formation if deficiency exists.
3) Vitamin D supports bones. 4) Calcium supports bone health.
5) Vitamin C should be used carefully because it can affect iron handling and is not routine in iron overload states without medical advice.
6) Multivitamin without iron may help poor intake.
7) Protein supplement may help undernourished patients.
8) Omega-3 may support general nutrition but is not disease-specific.
9) Zinc is used only if deficiency exists.
10) Magnesium may be used if low from diet or other illness. These should be individualized because some “anemia supplements” contain iron and may be unsafe in iron-loading disorders. [43]
Immunity, regenerative, or stem-cell related drugs.
There are no FDA-approved “immunity booster” or regenerative drugs specifically for CDA type III. In rare advanced settings, specialists may use supportive hematopoietic drugs.
1) Filgrastim is a G-CSF product used to raise neutrophils in approved settings.
2) Pegfilgrastim is a longer-acting G-CSF.
3) Sargramostim is GM-CSF.
4) Plerixafor helps mobilize stem cells for transplant collection with G-CSF.
5) Epoetin alfa supports red cell production in selected settings.
6) Darbepoetin alfa is a longer-acting ESA. These are not standard routine therapy for ordinary CDA III care and should only be used by specialists when there is a clear reason. [44]
Surgeries or procedures.
1) Blood transfusion procedure is the most common supportive procedure when anemia is severe. 2) Central venous access placement may be needed in complex long-term care. 3) Splenectomy is not routine for CDA III and has less clear value than in some other CDA types, but it may be discussed rarely for selected complications. 4) Cholecystectomy may be needed if gallstones become symptomatic. 5) Hematopoietic stem cell transplantation is an exceptional curative-intent procedure for very severe cases, but risk is high and evidence in CDA III is limited. [45]
Prevention points.
Do regular follow-up, avoid self-started iron pills, keep vaccines updated, treat infections early, check ferritin and liver function regularly, get iron MRI when advised, avoid alcohol excess, keep eye follow-up if your doctor advises it, ask for genetic counseling before pregnancy, and use only hematologist-guided transfusion and chelation plans. These steps cannot prevent the gene defect, but they can prevent many complications. [46]
When to see a doctor urgently.
Seek medical help fast for chest pain, fainting, severe weakness, fast breathing, blue lips, dark urine, fever, yellow eyes getting worse, severe belly pain, new vision changes, palpitations, swelling, or signs of transfusion reaction. Also seek help if you become much more tired than usual or cannot do normal daily activity. [47]
What to eat and what to avoid.
Eat balanced meals with enough protein, folate-rich foods, B12-rich foods if allowed, fruits, vegetables, beans, eggs, fish, and adequate fluids. Avoid routine iron supplements unless deficiency is proven. Be careful with heavily iron-fortified products if your doctor says you have iron overload. Limit alcohol, avoid smoking, avoid unregulated “blood builder” supplements, avoid skipping meals, avoid dehydration, avoid raw or unsafe foods during illness, and avoid herbal products that may injure the liver. [48]
FAQs.
1) Is CDA type III curable? Usually no, but selected very severe cases may be considered for transplant.
2) Is it inherited? Yes. 3) Is it the same as iron deficiency anemia? No. 4) Can iron be high even when someone has anemia? Yes. 5) Does every patient need transfusions? No. 6) Is there a special FDA-approved CDA III drug? No. 7) Can vision problems happen? Sometimes. 8) Can adults need screening for plasma cell disease? In some families, yes. 9) Is bone marrow testing useful? Yes, especially for diagnosis. 10) Can pregnancy need specialist care? Yes. 11) Should I take iron by myself? No. 12) Can ferritin alone tell the whole story? Not always; MRI may help. 13) Can chelation help? Yes, if iron overload is present. 14) Should children and relatives consider testing? Often yes, after counseling. 15) Can symptoms stay mild for years? Yes, some people are diagnosed late because disease severity varies. [49]
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: April 01, 2025.
