What is Aase Syndrome: Causes, Symptoms, Treatment, Pictures, Diagnosis, Prognosis, Life Expectancy in Children and Infants

Also called Aase-Smith Syndrome II, this condition was first described by doctors Jon Morton Aase and David Weyhe Smith in 1968.

Definition

Aase Syndrome (also known as Aase-Smith syndrome, type II) is a rare genetic condition mainly characterized by congenital hypoplastic anemia and some joint and skeletal deformities, such as triphalangeal thumbs and other abnormalities in fingers and feet. Due to its defining features, it is also called Congenital Anemia-Triphalangeal Thumb Syndrome.

What is Aase Syndrome?

Aase Syndrome is a rare genetic condition present at birth. It is marked by:

• Hypoplastic anemia – Anemia due to the bone marrow’s inability to produce red blood cells.
• Triphalangeal thumbs – Thumbs that have three bones instead of the usual two, making them look more like fingers.

The presence of both features is typically essential for diagnosis. The severity can differ from one individual to another, influencing long-term outcomes.

Who Gets Aase Syndrome?

It affects males and females equally and is generally detected early in life. While some cases follow an autosomal recessive inheritance, the exact cause of most cases remains unknown. Fewer than 20 cases have been documented globally, making it one of the rarest known congenital conditions.

Risk Factors of Aase Syndrome

• Inherited cases: A small percentage follow an autosomal recessive gene mutation.
• No family history: Most cases occur sporadically with no known inheritance pattern.

Risk factors don’t necessarily lead to the condition; not having them doesn’t provide protection. If you have a family history of genetic disorders, consult a healthcare provider.

What Causes Aase Syndrome?

Although the cause is unclear, researchers have linked it to mutations in several ribosomal protein genes, including:

• RPL5, RPL11, RPL35A
• RPS7, RPS10, RPS17, RPS19, RPS24, RPS26

These genes are vital in ribosome formation and essential for producing cell proteins. Mutations can:

• Disrupt ribosome function
• Lead to poor blood cell production
• Cause bone marrow cells to undergo apoptosis (cell death)
• Impairs cell division, contributing to developmental issues

Aase Syndrome – Symptoms and Signs

While the most recognized symptoms are hypoplastic anemia and triphalangeal thumbs, other signs include:

• Pale skin
• Slowed or delayed growth
• Skull fontanels (soft spots) that close late
• Narrow shoulders
• Joint contractures (joints that can’t fully extend)
• Abnormal or deformed ears
• Cleft palate
• Droopy eyelids
• Small knuckles, triple-jointed thumbs, and fewer skin creases

Diagnosis of Aase Syndrome

A proper diagnosis requires a thorough clinical evaluation and tests such as:

• Physical examination and family history
• CBC (Complete Blood Count): Shows low red and possibly white blood cell counts
• X-rays: Reveal skeletal issues like triphalangeal thumbs
• Echocardiography: Used to detect heart defects like Ventricular Septal Defect (VSD)
• Bone marrow biopsy: To confirm reduced bone marrow function

Because several conditions mimic Aase Syndrome, further testing may be needed to rule out other diagnoses.

Aase Syndrome Complications

• Fatigue and weakness due to chronic anemia
• Heart failure caused by congenital disabilities like VSD
• Recurrent infections resulting from low white blood cell counts (leukopenia)
• Increased risk of early death, especially in severe cases
• Stillbirths, though rare

Treatment Options for Aase Syndrome

While there is no cure, symptoms can be managed with:

1. Blood Transfusions

• Regular transfusions to manage anemia
• Often started during infancy

2. Bone Marrow Transplant

• Can improve anemia and leukopenia in some individuals

3. Steroid Therapy

• Drugs like prednisone may help in older children or adults
• Not advised for infants under 1 year old due to potential risks to brain development

4. Heart Surgery

• Needed to correct congenital disabilities like VSD

Prevention of Aase Syndrome

As a genetic disorder, complete prevention isn’t possible. However:

• Early detection and intervention can significantly improve the quality of life
• Genetic counseling is highly recommended for families with a history of Aase Syndrome
• Prompt treatment of infections and heart conditions can reduce complications during childhood

Prognosis and Life Expectancy

The outcome depends on how severe the symptoms are:

• Anemia can improve over time, lowering the need for transfusions
• Bone marrow function might recover over several years
• Leukopenia may remain, posing a risk of infections
• Severe heart defects can result in early death or stillbirth

With consistent medical care and close monitoring, many affected individuals can live relatively stable lives.

Conclusion

Aase Syndrome is a rare and potentially life-threatening genetic disorder that affects multiple body systems. Early diagnosis, proper medical management, and raising awareness are essential to improving outcomes. If you believe your child shows signs of Aase Syndrome, immediately see a pediatrician or genetics expert.

Read more about rare health conditions at Health Care Tips Hub. Stay informed. Stay healthy.