Osteopetrosis
Background
Osteopetrosis is a rare genetic disease which affects osteoclasts. These are cells which dissolve bone, so that it can be reshaped during growth or repaired after injury. This defect causes bones throughout the body to become excessively dense and to fracture easily. Nerves which sit in bony channels (such as those which pass through the skull to the eye or ear) can be damaged since these channels do not enlarge as the nerves grow.