Refractory anaemia with an excess of blasts

Refractory Anaemia with Excess Blasts

Refractory anaemia with excess blasts (R.A.E.B) is a type of myelodysplastic syndrome (MDS), a group of disorders caused by dysfunctional development of the bone marrow. It is characterized by low numbers of all cell lines, an excess of blasts in the bone marrow, and certain genetic mutations. The diagnosis of RAEB requires finding at least 10% blasts in the bone marrow. The presence of 20% or more blasts in the bone marrow is known as RAEB in transformation.


The most common symptoms of RAEB include:

  • Fatigue
  • Shortness of breath
  • Easy bruising/bleeding
  • Frequent infections
  • Paleness/pallor
  • Rapid heart rate

Risk Factors

Exposure to certain environmental toxins, such as benzene, is thought to play a role in the development of RAEB. Additionally, certain inherited genetic mutations have been found in people with RAEB, including mutations to the genes TET2, JAK2, and DNMT3A.


A diagnosis of RAEB is made through both clinical presentation and laboratory testing. Blood tests are usually done to confirm a diagnosis, including a complete blood count (CBC) and a bone marrow biopsy.


Treatment for RAEB is typically symptomatic. Patients may receive blood or platelet transfusions to help boost their blood count. Additionally, they may be prescribed medications to boost their immune systems and reduce fatigue. In some cases, a stem cell transplant may be recommended. Other treatments may include radiation therapy or chemotherapy.


The prognosis for people with RAEB is typically worse than other types of MDS, though it varies greatly from person to person. Unfortunately, most cases of RAEB progress to acute myeloid leukemia (AML). However, with prompt and effective treatment, it is possible to achieve remission.