The severity of the disease varies with the type. It can range from a "malignant" form that is lethal during infancy to a relatively mild condition that improves with age.
Defective bone development:
(1) brittle bones subject to pathologic fracture
Insufficient medullary space within bones:
(1) hepatosplenomegaly secondary to extramedullary hematopoiesis
(2) thrombocytopenia
(3) anemia
(4) neutropenia with infection
Failure to enlarge foramina in the skull:
(1) visual defects with strabismus (squinting)
(2) compression of other cranial nerves (facial nerve, acoustic nerve, other)
Imaging findings:
(1) increased bone density
(2) "bone in bone" appearance
(3) transverse banding of metaphyses
(4) delay or failure to form the normal tubulation of long bones
