Defining Characteristics
Disproportionate (big head, small body), pectus excavatum, lumbar lordosis, nail hypoplasia (missing nails)
Facial dysmorphism? Missing jaw look, large forehead, underdeveloped nose, asymmetry
Disease Development
Mutation/defect in cathepsin K, so osteoclasts can no longer function properly in bone resorption
Potential Causes
Bone overgrowth due to loss of osteoclast resorptive fx
Epidemiology
Onset in infancy, early childhood
Very rare!
Lab/Imaging
XR? Dense orbital ridge, sclerotic skull base, hypoplasia of facial bones, dense vertebrae w/ preservation of TVP
Complications
Recurrent fractures in lower limbs