Aase syndromeAase-Smith syndrome; Hypoplastic anemia - triphalangeal thumbs, Aase-Smith type
Aase syndrome is a rare disorder that involves anemia and certain joint and skeletal deformities.
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 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
The health care provider will perform a physical exam. Tests that may be done include:
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.
The anemia tends to improve with age.
Complications related to anemia include:
- Decreased oxygen in the blood
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.
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. Gene Reviews. Seattle, WA: University of Washington; 2014:9. PMID: 20301769 www.ncbi.nlm.nih.gov/pubmed/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.
Review Date: 8/1/2015
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Fullerton Genetics Center, Asheville, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.