Bruck syndrome 2
Definition An autosomal recessive disorder (OMIM:609220) characterised by generalised osteopenia, congenital joint contractures, fragile bones with onset of fractures in infancy or early childhood, short stature, severe limb deformity, clubfoot, congenital joint limitations, progressive scoliosis, and pterygia.
In contrast to osteogenesis imperfecta, hearing loss and dentinogenesis imperfecta are absent.
Pathogenesis Bruck syndrome is caused by an aberrant cross-linking of bone collagen, due to underhydroxylation of lysine residues within the telopeptides of type I collagen (the lysine residues in the triple helix are normal).
Molecular pathology Defects of PLOD2, which encodes an enzyme* that hydroxylates lysyl residues in collagen-like peptides, providing attachment sites for carbohydrates in collagen, cause Bruck syndrome 2.
*Procollagen-lysine—2-oxoglutarate 5-dioxygenase 1
Synonym Osteogenesis imperfecta with congenital joint contractures