Aase Syndrome

Condition 101

What is the definition of Aase Syndrome?

Aase syndrome is a rare disorder that involves anemia and certain joint and skeletal deformities.

What are the alternative names for Aase Syndrome?

Aase-Smith syndrome; Hypoplastic anemia - triphalangeal thumbs, Aase-Smith type; Diamond-Blackfan with AS-II

What are the causes for Aase Syndrome?

Many cases of Aase syndrome occur without a known reason and are not passed down through families (inherited). However, some cases (45%) have been shown to be inherited. These are due to a change in 1 of 20 genes important for making protein correctly (the genes make ribosomal proteins).

This condition is similar to Diamond-Blackfan anemia, and the two conditions should not be separated. A missing piece on chromosome 19 is found in some people with Diamond-Blackfan anemia.

The anemia in Aase syndrome is caused by poor development of the bone marrow, which is where blood cells are formed.

What are the symptoms for Aase Syndrome?

Symptoms may include:

  • Absent or small knuckles
  • Cleft palate
  • Deformed ears
  • Droopy eyelids
  • Inability to fully extend the joints from birth
  • Narrow shoulders
  • Pale skin
  • Triple-jointed thumbs

What are the current treatments for Aase Syndrome?

Treatment may involve blood transfusions in the first year of life to treat anemia.

A steroid medicine called prednisone has also been used to treat anemia associated with Aase syndrome. However, it should only be used after reviewing the benefits and risks with a provider who has experience treating anemias.

A bone marrow transplant may be necessary if other treatment fails.

What is the outlook (prognosis) for Aase Syndrome?

The anemia tends to improve with age.

What are the possible complications for Aase Syndrome?

Complications related to anemia include:

  • Fatigue
  • Decreased oxygen in the blood
  • Weakness

Heart problems can lead to a variety of complications, depending on the specific defect.

Severe cases of Aase syndrome have been associated with stillbirth or early death.

How do I prevent Aase Syndrome?

Genetic counseling is recommended if you have a family history of this syndrome and wish to become pregnant.


Clinton C, Gazda HT. Diamond-Blackfan anemia. GeneReviews. 2014:9. PMID: 20301769 Updated March 7, 2019. Accessed July 31, 2019.

Gallagher PG. The neonatal erythrocyte and its disorders. In: Orkin SH, Fisher DE, Ginsburg D, Look AT, Lux SE, Nathan DG, eds. Nathan and Oski's Hematology and Oncology of Infancy and Childhood. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 2.

Thornburg CD. Congenital hypoplastic anemia (Diamond-Blackfan anemia). In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 475.

Latest Research

Latest Advance
  • Condition: Diamond-Blackfan anemia
  • Journal: Blood advances
  • Treatment Used: Hematopoietic stem cell transplantation
  • Number of Patients: 70
  • Published —
The study researched the outcomes of hematopoietic stem cell transplantation for children and adolescents with Diamond-Blackfan anemia.
Latest Advance
  • Condition: Moderate Aplastic Anemia or Uni-Lineage Cytopenias
  • Journal: Blood advances
  • Treatment Used: Eltrombopag
  • Number of Patients: 34
  • Published —
This study tested the safety and efficacy of using eltrombopag to treat patients with moderate aplastic anemia or uni-lineage cytopenias.
Latest Advance
  • Condition: Elderly Patients with Myelodysplastic Syndrome (MDS)
  • Journal: Biological & pharmaceutical bulletin
  • Treatment Used: L-Leucine Therapy
  • Number of Patients: 8
  • Published —
This study investigated the effects of L-leucine on hematopoietic function (reticulocyte count), red blood cell count, and hemoglobin level in patients with myelodysplastic syndrome (MDS).

Clinical Trials

Clinical Trial
  • Status: Recruiting
  • Study Type: Drug
  • Participants: 25
  • Start Date: September 9, 2020
Treatment of Refractory Diamond-Blackfan Anemia With Eltrombopag
Clinical Trial
  • Status: Recruiting
  • Study Type: Drug
  • Participants: 58
  • Start Date: December 7, 2017
A Phase II Trial of Haploidentical Allogeneic Stem Cell Transplantation Utilizing Mobilized Peripheral Blood Stem Cells