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

• BD (Boomerang Dysplasia)
• Boomerang-like Skeletal Dysplasia
• Dwarfism with Short, Bowed, Rigid Limbs and Characteristic Facies

What is Boomerang Dysplasia? (Definition/Background Information)

• Boomerang Dysplasia (BD) is a rare lethal skeletal dysplasia characterized by severe short-limbed dwarfism, dislocated joints, club feet, distinctive facies and diagnostic X-ray findings of underossified and dysplastic long tubular bones, with a boomerang-like bowing
• Affected neonates are stillborn or die rapidly after birth and present clinically with severe short-limbed dwarfism, dislocated hip, knee and elbow joints, club feet and proviso born alive have severe cardio respiratory failure
• Facial dysmorphism includes midface hypoplasia and cleft palate. Boomerang Dysplasia clinically differs from AOI and AOIII because of the boomerang shaped bowing of the femur and occasionally observed encephalocele and omphalocele

(Source: Boomerang Dysplasia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets Boomerang Dysplasia? (Age and Sex Distribution)

• Boomerang Dysplasia is a rare congenital disorder of unknown prevalence
• The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Boomerang Dysplasia? (Predisposing Factors)

• A positive family history may be an important risk factor, since it is believed that Boomerang Dysplasia can be inherited
• Currently, no other risk factors have been clearly identified for this syndrome

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 Boomerang Dysplasia? (Etiology)

• Boomerang Dysplasia results from missense mutations or small in-frame deletions in the FLNB gene reported in exons 2-5, normally expected to translate full length but biochemically abnormal filamin B protein

(Source: Boomerang Dysplasia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

What are the Signs and Symptoms of Boomerang Dysplasia?

The signs and symptoms of Boomerang Dysplasia may include:

• Absent radius
• Fibular aplasia
• Hypoplastic iliac body
• Hypoplastic nasal septum
• Severe short stature
• Underdeveloped nasal alae
• Wide nasal bridge

Based on the frequency of symptoms observed, the following information may be noted:

Very frequently present symptoms in 80-99% of the cases:

• Abnormality of tibia morphology
• Aplasia/hypoplasia of the fibula
• Growth hormone deficiency
• Micromelia
• Narrow chest
• Poorly ossified vertebrae
• Severe short-limb dwarfism

Frequently present symptoms in 30-79% of the cases:

• Abnormality of femur morphology 
• Abnormality of the humerus 
• Abnormality of the metacarpal bones    
• Abnormality of the radius 
• Aplasia/hypoplasia of the abdominal wall musculature
• Aplasia/hypoplasia of the lungs 
• Cryptorchidism 
• Finger syndactyly 
• Hydrops fetalis 
• Omphalocele 
• Polyhydramnios

Occasionally present symptoms in 5-29% of the cases: 

• Abnormality of the ulna

(Source: Boomerang Dysplasia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Boomerang Dysplasia Diagnosed?

Diagnosis of Boomerang Dysplasia can be confirmed from skeletal radiographs, chondro-osseous histopathology and genetic testing.

• Distinctive radiographic findings are similar to AOI but, BD presents with a more severe deficiency in mineralization, with non-ossification of certain segments of limbs and vertebrates, and a boomerang-like shape of some long tubular bones
• Differential diagnosis comprises other skeletal dysplasias with severe short-limbed dwarfism such as achondrogenesis, campomelic dysplasia, Ellis-van Creveld syndrome, achondroplasia, metatropic dysplasia, Roberts syndrome, short rib-polydactyly syndrome and thanatophoric dysplasia
• Additional differential diagnosis includes diseases associated with impaired ossification such achondrogenesis, hypophosphatasia, and osteogenesis imperfecta (see these terms)
• The prenatal diagnosis of BD is difficult to ascertain by ultrasound
• Ultrasound shows thoracic hypoplasia, limb shortening, delayed ossification of spine and appendicular segments and possibly joint dislocations, similar to AOI and AOIII
• Boomerang-shape morphology some long tubular bones may be diagnosed prenatally by 3D-CT scan

(Source: Boomerang Dysplasia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

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 Boomerang Dysplasia?

The complications of Boomerang Dysplasia may include:

• Severe abnormalities affecting the bone and other body parts
• Cardio-respiratory failure
• Neonatal death, in many cases

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

How is Boomerang Dysplasia Treated?

There is no cure for Boomerang Dysplasia, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complications that develops.

How can Boomerang Dysplasia be Prevented?

Currently, Boomerang Dysplasia may not be preventable, since it is reportedly a genetic disorder.

• 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 genetic disorders

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

What is the Prognosis of Boomerang Dysplasia? (Outcomes/Resolutions)

• The prognosis of Boomerang Dysplasia is poor, as the condition is lethal in utero
• Affected neonates are stillborn or die rapidly after birth

(Source: Boomerang Dysplasia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Additional and Relevant Useful Information for Boomerang Dysplasia:

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

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