Aase syndrome is a very rare disease with an unknown genetic cause. Very few cases have been reported in medical literature. It is estimated that this rare disease affects less than one in one million people.

Aase syndrome is a rare disease present from birth that is hypothesized to be caused by a genetic mutation. There is currently no known genes associated with Aase syndrome, yet inheritance patterns indicate that this rare disease is passed from parents to their children through autosomal dominant inheritance. However, only about 45% of reported cases have a family member with Aase syndrome, therefore most people diagnosed with Aase syndrome have a random mutation causing this rare disease. There is a possibility that multiple genetic factors may cause Aase syndrome, but more research is needed in this area.

One symptom that can develop in children with Aase syndrome is anemia, or low red blood cell count due to underdeveloped bone marrow. Researchers have identified 20 possible genes that could influence bone marrow development. These genes are involved in producing ribosomes, or proteins that are crucial to the development of other proteins. More research is needed to determine the genetic link to Aase syndrome.

Aase syndrome is most commonly diagnosed on the basis of characteristic physical features that are shared among children with this rare disease. These physical traits include:

• Thin or elongated fingers

• Lack of finger knuckles and reduced creases over finger joints

• Inability to make a fist with the hands

• Deformed ears

• Drooping eyelids

• Cleft-palate

• Clubfoot

• Bilateral triphalangeal thumbs - thumbs have an extra long finger-like appearance with an extra joint

• Poor peripheral vision

• Difficulty extending joints or rigid movement

• Mild growth deficiency

Other areas of the body can be affected by Aase syndrome including:

• Heart defects due to lower levels of oxygen in the blood

• Pressure build-up and other side effects in the brain due to cerebrospinal fluid entering cavities within the brain

• Hypoplastic anemia or low red blood cell production due to abnormal or low bone marrow

Children may experience low energy or fatigue as a result of lower red blood cell count and a lack of nutrients being delivered within their body. One of these deficiencies can be iron, and children with low iron can display symptoms such as attempting to eat iron-rich materials like clay, dirt, or starch. These behaviors should be monitored and can indicate treatments that will help individual cases.

Aase syndrome is commonly diagnosed by doctors examining children with physical features characteristic of the rare disease. The hands are especially important in this diagnosis, as children with abnormally long thumbs with an extra joint (bilateral triphalangeal thumbs) usually develop this feature within the first 6 months of life. It is important to diagnose this disease as early as possible in order to receive personalized treatment and care and prevent organ damage or side effects due to anemia. Physical abnormalities coupled with a diagnosis of hypoplastic anemia indicates a diagnosis of Aase syndrome.

Once a diagnosis of Aase syndrome is suspected due to physical characteristics, a number of tests can be employed to confirm a diagnosis:

• X-ray echocardiogram - Red blood cell count compared to a healthy level indicates whether levels are lower 

• Bone marrow biopsy - Extracting a small amount of soft tissue from inside the bone to compare its red blood cell production to healthy bone marrow

There is no cure for Aase syndrome, and thus treatment plans must be tailored to fit the needs of the individual with the rare disease. Some children may require blood transfusions and medication to treat hypoplastic anemia. Others may require mineral supplements such as iron and other vitamins. This anemia may lessen with growth as the bones develop and more marrow is available to produce more red blood cells. In extreme cases of anemia, a bone marrow transplant may be necessary.

There are surgical procedures available to treat physical abnormalities associated with Aase syndrome. Many of these procedures are optional, and may be recommended on a case-by-case basis if the feature is affecting the child’s quality of life.

Aase syndrome is commonly diagnosed at birth or during early childhood. Mindful monitoring of symptoms, especially anemia, and appropriate treatment can maintain a healthy lifestyle and prevent further complications. Anemia in young children can increase their risk of developing diseases such as leukemia, and their red blood cell count and bone marrow should be monitored to maintain a healthy prognosis. Additionally, precautions should be taken if a person diagnosed with Aase syndrome is to undergo a procedure requiring anesthesia. Hypoplastic anemia can lead to complications and certain considerations such as measuring red blood cell count should be taken to maintain healthy oxygen levels.

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