What are the other Names for this Condition? (Also known as/Synonyms)

• Autosomal Dominant Otospondylomegaepiphyseal Dysplasia
• Pierre Robin Syndrome with Fetal Chondrodysplasia
• Stickler Syndrome, Non-Ocular type

What is Weissenbacher-Zweymuller Syndrome? (Definition/Background Information)

• Weissenbacher-Zweymuller Syndrome (WZS) is an extremely rare congenital disorder that is associated with improper bone formation, short stature, loss of hearing, and characteristic (abnormal) facial features. The disorder is also known as Heterozygous Otospondylomegaepiphyseal Dysplasia
• It is an autosomal dominant genetic disorder affecting newborn children. Weissenbacher-Zweymuller Syndrome is caused by heterozygous mutations in the COL11A2 gene. Thus, a family history of the disorder is a risk factor for inheriting the condition
• There is no effective treatment for Weissenbacher-Zweymuller Syndrome. The complications, such as cataract, retinal detachments, and hearing loss, should be treated appropriately. Routine eye and ear examination is recommended
• Weissenbacher-Zweymuller Syndrome is also not preventable. However, parents may undergo genetic counselling and genetic tests to understand the risks better. The prognosis of WZS depends on its severity and this can vary on a case-by-case basis

Who gets Weissenbacher-Zweymuller Syndrome? (Age and Sex Distribution)

• Weissenbacher-Zweymuller Syndrome is an extremely rare congenital disorder. Only a few families have been reported worldwide in the medical literature with the disorder
• The presentation of symptoms may occur at birth or in infancy
• Both males and females are known to be affected, and no gender preference is seen
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors of Weissenbacher-Zweymuller Syndrome? (Predisposing Factors)

• A positive family history may be an important risk factor, since Weissenbacher-Zweymuller Syndrome can be inherited
• Currently, no other risk factors have been clearly identified for the disorder

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Weissenbacher-Zweymuller Syndrome? (Etiology)

• Weissenbacher-Zweymuller Syndrome is a genetic disorder that is caused by an autosomal dominant mutation in the COL11A2 gene
• The specific gene involved is responsible for the formation of type XI collagen in the bones and cartilages

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition, or pass it on to their offspring.

What are the Signs and Symptoms of Weissenbacher-Zweymuller Syndrome?

The signs and symptoms of Weissenbacher-Zweymuller Syndrome may vary from one individual to another can be mild or severe. These may include:

• Ocular signs and symptoms:
  • Short-sightedness
  • Congenital glaucoma (increased intraocular pressure)
• Abnormal facial features:
  • Flat occiput (back of skull) and flat face
  • Low nasal bridge; upturned tip of nose
  • Small mouth with protruding tongue
  • High-arched roof of the nose
  • Short neck
• Weak muscle tone (hypotonia)
• Skeletal abnormalities involving the limbs and pelvic girdle; 'dumbbell' shaped arm and leg bones may be observed
• Short limbs and overall short stature
• Conductive or sensorineural hearing impairment
• Delayed gross motor development
• Speech and language development delays

How is Weissenbacher-Zweymuller Syndrome Diagnosed?

Weissenbacher-Zweymuller Syndrome is diagnosed on the basis of the following information:

• Complete physical examination and thorough medical history evaluation
• Assessment of presenting signs and symptoms
• Hearing and vision assessment
• Laboratory tests, as needed
• Imaging studies of the affected region
• Molecular genetic testing to check for or confirm specific causative gene mutation(s): A sequence analysis of the entire coding region is needed to diagnose Weissenbacher-Zweymuller Syndrome
• Prenatal testing including abdominal ultrasound scans

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Weissenbacher-Zweymuller Syndrome?

If left untreated, Weissenbacher-Zweymuller Syndrome can cause complications such as the following:

• Severe emotional and psychological stress for the parents and caregivers
• Global developmental delays
• Corneal tears
• Retinal detachment
• Cataracts
• Severe pain in joints
• Progressive loss of hearing that may be permanent
• Attention-deficit hyperactivity disorder (ADHD) and associated behavioral problems
• Reduced quality of life

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Weissenbacher-Zweymuller Syndrome Treated?

There is no cure for Weissenbacher-Zweymuller Syndrome since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops.

• Physical therapy
• Use of vision and hearing aids
• Surgery to correct vision, hearing, and other defects, if required
• Occupational therapy and support
• Speech and language assistance

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

How can Weissenbacher-Zweymuller Syndrome be Prevented?

Weissenbacher-Zweymuller Syndrome may not be preventable since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired disorders

What is the Prognosis of Weissenbacher-Zweymuller Syndrome? (Outcomes/Resolutions)

• The prognosis of Weissenbacher-Zweymuller Syndrome is dependent upon the severity of the signs and symptoms and associated complications, if any present
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Weissenbacher-Zweymuller Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/