Boomerang dysplasia

Boomerang dysplasia is an extremely rare and lethal skeletal disorder (osteochondrodysplasia) characterized by severe dwarfism and distinctive skeletal abnormalities that are apparent prenatally or at birth. The name derives from the characteristic boomerang-shaped appearance of the long bones, particularly the femora, seen on radiographic imaging. This condition is caused by heterozygous mutations in the FLNB gene (filamin B), which plays a critical role in skeletal development and cartilage formation. Boomerang dysplasia is considered the most severe condition within the spectrum of FLNB-related skeletal disorders, which also includes atelosteogenesis types I and III and Larsen syndrome. The disease profoundly affects the skeletal system, with key features including severe limb shortening (micromelia), underossification (reduced mineralization) of the vertebral bodies and limb bones, absent or severely hypoplastic long bones with the characteristic boomerang shape, encephalocele (protrusion of brain tissue through the skull), and distinctive facial features including a flat midface, widely spaced eyes (hypertelorism), and a depressed nasal bridge. Additional findings may include omphalocele, finger and nail abnormalities, and dislocated joints. The thorax is often narrow and underdeveloped. Boomerang dysplasia is uniformly lethal, with affected individuals typically dying in utero or in the early neonatal period due to respiratory insufficiency related to the severely underdeveloped thorax and lungs. There is no curative treatment available. Management is limited to supportive and palliative care. Prenatal diagnosis may be possible through ultrasound identification of the characteristic skeletal abnormalities and can be confirmed by molecular genetic testing of the FLNB gene. Genetic counseling is recommended for affected families.

Common questions about Boomerang dysplasia