Aase-Smith syndrome is a rare hereditary condition characterized by deformities of the thumb, hypoplastic anemia and possibly other craniofacial abnormalities. The syndrome, which is also known as “congenital anemia-triphalangeal thumb syndrome” has a whole range of symptoms that are never all present at the same time. Complications can be limited or avoided through a rapid diagnosis. The syndrome is extremely rare, which means that almost no scientifically substantiated information can be found and few case reports are available. American pediatricians Jon Morton Aase and David Weyhe Smith first described Aase-Smith syndrome in 1968.
- Synonyms Aase-Smith syndrome
- Epidemiology Aase-Smith syndrome
- Causes of illness
- Symptoms: Anemia (anemia), thumbs
- Diagnosis and examinations
- Therapy
- Prognosis condition
Synonyms Aase-Smith syndrome
The following synonyms are known for Aase-Smith syndrome (BDA, BDS, DBA):
- Aase-Smith syndrome II
- Aase syndrome
- Diamond Blackfan anemia
- Blackfan-Diamond disease
- Blackfan-Diamond syndrome
- chronic congenital agenerative anemia
- congenital erythroid hypoplastic anemia
- Blackfan and Diamond congenital hypoplastic anemia
- congenital pure red cell anemia
- congenital pure red cell aplasia
- erythrogenesis imperfecta
- hypoplastic congenital anemia
- inherited erythroblastopenia
- purely hereditary red cell aplasia
Epidemiology Aase-Smith syndrome
The incidence of Aase-Smith syndrome is <1/1 000 000. The syndrome has no gender preference. The medical literature only mentions a few dozen patients, making the syndrome extremely rare.
Causes of illness
The exact cause of Aase-Smith syndrome is unknown. However, most scientific studies suggest that the condition is inherited in an autosomal recessive manner. The genetic basis of the disease is unknown. Underdevelopment of the bone marrow (the formation of blood cells takes place in the bone marrow) causes anemia.
Symptoms: Anemia (anemia), thumbs
Some primary symptoms are typical of Aase-Smith syndrome:
- hypoplastic anemia : medical term for “abnormally reduced production of red blood cells”
- triphalangeal thumbs : one or two thumbs with three phalanges (bones)
Many other symptoms are also possible:
- absent or small knuckles
- pale skin
- anemia: This manifests itself in fatigue and weakness.
- cleft palate
- drooping eyelids
- heart defect: It usually concerns a ventricular septal defect; this is a hole between the lower chambers of the heart.
- cleft lip
- smaller number of skin folds at the finger joints
- late closure of the fontanelles (soft spots in the skull)
- deformed ears
- underdeveloped forearms
- inability to fully extend joints: this is present from birth (contracture deformity)
- narrow shoulders
Diagnosis and examinations
Clinical research
In most patients with Aase-Smith syndrome, the physician makes the diagnosis during early childhood based on a thorough clinical examination, identification of characteristic physical findings, and various specialized investigations.
Blood tests
A thorough blood test confirms congenital hypoplastic anemia. It is important that the doctor detects this syndrome as soon as possible to avoid complications.
Imaging
Diagnostic studies include a CT scan, MRI scan or other diagnostic studies such as an echocardiogram in detecting and imaging the skeletal system or other abnormalities associated with the syndrome.
Biopsy
A bone marrow biopsy is also possible.
Differential diagnosis
The differential diagnoses include Diamond Blackfan anemia (congenital form of anemia), Fanconi anemia, Holt-Oram syndrome and TAR syndrome.
Therapy
The treatment of Aase-Smith syndrome is focused on the specific symptoms the patient exhibits. This requires close collaboration between medical professionals such as surgeons, pediatricians, hematologists, orthopedists, and physicians who diagnose and treat disorders of the skeleton, joints, muscles, and related tissues.
The anemia associated with Aase-Smith syndrome often responds to corticosteroid treatment, such as prednisone treatment. In addition, the literature reports that prednisone therapy has clearly and definitively ended the anemia (remission). In a number of patients, the body does not respond sufficiently to treatment with corticosteroids. In that case, periodic blood transfusions are necessary.
However, some complications are possible due to repeated transfusions:
- abnormally low platelets in the blood (secondary thrombocytopenia),
- the liver and spleen are sometimes abnormally enlarged (hepatosplenomegaly: (enlarged liver) and enlarged spleen),
- excessive deposition of iron in various tissues (hemosiderosis), and/or
- other complications.
In that case, additional supportive therapies are needed, such as iron-binding medications that enable the body to excrete iron. Some cases of anemia require other therapies if they do not respond to corticosteroids, such as a bone marrow transplant. Sometimes corrective and reconstructive surgery is recommended to correct certain craniofacial malformations, skeletal abnormalities and/or other physical abnormalities. The surgical procedure used depends on the severity and location of the anatomic abnormality, associated symptoms and other factors. Other treatment options for this condition are symptomatic and supportive.
Prognosis condition
According to reports in the medical literature, anemia associated with Aase-Smith syndrome improves as the patient ages.
read more
- Anemia (anemia): Types of red blood cell deficiency
- Anemia (deficiency of red blood cells): Types and causes
