Home > Encyclopedia of Children's Health > Osteopetroses

Definition

Osteopetrosis (plural osteopetroses) is a rare inherited disorder that makes bones increase in both size (mass) and fragility. It is a potentially fatal condition that can deform bone structure and distort the appearance. Osteopetrosis is also called chalk bones, ivory bones, or marble bones.

Description

In healthy individuals, bones are constantly being broken down (resorption) by cells called osteoclasts, and new bone material is constantly being formed by cells called osteoblasts. Osteopetrosis occurs when there is a failure in bone resorption. The mass of bone increases, but the new bone material that is added is porous, weak, and brittle.

There are three types of osteopetrosis. In some children with osteoporosis, bone mass begins to increase at birth, but symptoms may...