Aase syndrome

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

  • Alternative Names
    • Aase-Smith syndrome; Hypoplastic anemia - triphalangeal thumbs, Aase-Smith type

  • Causes
    • 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 9 genes important for making protein correctly (the genes make ribosomal proteins)

      This condition is similar to Diamond-Blackfan anemia, and the 2 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.

  • Symptoms
    • Symptoms may include:

      • Absent or small knuckles
      • Cleft palate
      • Decreased skin creases at finger joints
      • Deformed ears
      • Droopy eyelids
      • Inability to fully extend the joints from birth (contracture deformity)
      • Narrow shoulders
      • Pale skin
      • Triple-jointed thumbs
  • Exams and Tests
  • Treatment
    • 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.

  • Outlook (Prognosis)
    • The anemia tends to improve with age.

  • Possible Complications
    • 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.

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

  • References
    • Clinton C, Gazda HT. Diamond-Blackfan anemia. Gene Reviews. Seattle, WA: University of Washington; 2014:9. PMID: 20301769 Accessed August 1, 2015.

      Jones KL, Jones MC, Del Campo M. Facial-limb defect as major feature. In: Jones KL, Jones MC, Del Campo M, eds. Smith's Recognizable Patterns of Human Malformation. 7th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap I.