Thrombocytopenia With Congenital Dyserythropoietic Anemia

Thrombocytopenia with congenital dyserythropoietic anemia (CDA; see this term) is a rare hematological disorder, seen almost exclusively in males, characterized by moderate to severe thrombocytopenia with hemorrhages with or without the presence of mild to severe anemia.

Epidemiology

The prevalence is unknown. At least 3 families have been described with thrombocytopenia with CDA and GATA1 mutations in the literature.

Clinical description

The disease affects mainly males as females are usually asymptomatic or have only mild symptoms. It presents in infancy or in neonates (in severe cases) with patients bruising easily along with further manifestations of thrombocytopenia including epistaxis, petechiae, ecchymoses, or splenomegaly. Anemia is often present but can range from mild to severe. Excessive hemorrhage and/or bruising can occur in some patients after trauma or spontaneously in others. Cryptorchidism has also been reported in several cases.

Etiology

The disease is caused by mutations in the GATA1 (Xp11.23) gene encoding GATA1, a transcriptional regulator involved in erythropoiesis and megakaryocytopoiesis. Different mutations found in this gene account for a variable phenotypic spectrum of disorders.

Diagnostic methods

Diagnosis is based on family history of the disease and laboratory findings. Blood count reveals thrombocytopenia, in some cases anemia, and very rarely neutropenia. Platelets often have functional abnormalities, shown by a defect in the aggregation response to agonists. Peripheral blood smear shows abnormal erythrocyte size and shape as well as paucity of platelets. Bone marrow biopsy can reveal dyserythropoiesis, dysmorphic erythroblasts, and dysplastic platelets and megakaryocytes. Molecular genetic testing can identify GATA1 mutations.

Differential diagnosis

Differential diagnosis includes myelodysplastic syndromes, thalassemias, Gilbert syndrome, hereditary spherocytosis, acute erythroid leukemia (see these terms), folate, iron or vitamin B12 deficiencies as well as infections such as AIDS, malaria (see this term), kala-azar or other acquired or inherited thrombocytopenias. Wiskott-Aldrich Syndrome (see this term) should also be excluded.

Antenatal diagnosis

Prenatal diagnosis is possible in families with a known GATA1 mutation.

Genetic counseling

The disease is inherited in an X-linked manner and genetic counseling is possible. Most females are asymptomatic carriers.

Management and treatment

Those with very mild symptoms do not require treatment. Thrombocytopenia related manifestations can be treated with platelet transfusions. For short-term mild to moderate bleeding, desmopressin may also be beneficial. Those with severe hydrops fetalis (see this term) related anemia will need an in utero transfusion and transfusions can be required after birth for those with severe anemia. Blood iron levels should be closely monitored in those undergoing regular transfusions. Bone marrow transplantation (BMT) can be considered in those with life-threatening manifestations. Antiplatelet agents, nonsteroidal anti-inflammatory agents and activities with a high risk of trauma should be avoided.

Prognosis

Prognosis depends on the severity of the disease. Quality of life may be affected in those with a serious form of the disease, and iron overload due to repeated blood transfusions to treat anemia can be very damaging if left untreated.