Bruck syndrome 1

Alternate names

Osteogenesis imperfecta with congenital joint contractures; BRKS1

Definition

Bruck syndrome is characterised by the association of osteogenesis imperfecta and congenital joint contractures.

Epidemiology

Prevalence is unknown but less than 40 cases have been reported in the literature so far.

Cause

The syndrome is genetically heterogeneous: the locus was mapped to chromosome 17p12 in one family (Bruck syndrome 1) but mutations in the PLOD2 gene (3q24) encoding telopeptide lysyl hydroxylase (Bruck syndrome 2) have been identified in other affected individuals.

Inheritance

Autosomal recessive inheritance, a 25% chance

Transmission is autosomal recessive.

Signs and symptoms

Features include osteoporosis and bone fragility, progressive joint contractures sometimes associated with pterygia, wormian bones, scoliosis due to vertebral deformities and short stature. Mental development is normal.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Arthrogryposis multiplex congenita
• Joint stiffness(Stiff joint)
• Osteoporosis
• Recurrent fractures(Increased fracture rate)
• Short stature(Decreased body height)
• Wormian bones(Extra bones within cranial sutures)

30%-79% of people have these symptoms

• Kyphosis(Hunched back)
• Pterygium
• Respiratory insufficiency(Respiratory impairment)
• Scoliosis
• Talipes equinovarus(Club feet)
• Triangular face(Face with broad temples and narrow chin)

5%-29% of people have these symptoms

• Bowing of the long bones(Bowed long bones)
• Platyspondyly(Flattened vertebrae)

Diagnosis

Diagnosis of Bruck syndrome must distinguish the association of contractures and skeletal fragility. Ultrasound is used for prenatal diagnosis. The diagnosis of a neonate bears resemblance to arthrogryposis multiplex congenital, and later in childhood to osteogenesis imperfecta.

Treatment

• Physical therapy and bracing proved helpful for the contractures to try to stop progression.
• Bone fragility needs to be considered when deciding to attempt cast correction.
• Surgeries in the soft tissues can be performed to retain joint movement.
• In fractures with angulation, intramedullary nail fixation was useful, and in cases without deformity, casting alone was successful.
• We suggest monitoring the bone density with DEXA, nutrition support with vitamin D and calcium, and treatment with bisphosphonates. Spine deformities were successfully treated by spinal fusion and instrumentation.