children s health issues
Osteochondrodysplasias
Introduction
Osteochondrodysplasias are a group of rare hereditary disorders of connective tissue, bone, or cartilage that cause the skeleton to develop abnormally. In osteochondrodysplasias, the growth and development of Bones , cartilage, and/or connective tissue is impaired usually because of mutations in the genes that play an important role in the development of connective tissue. Each type of osteochondrodysplasia causes different symptoms, but all osteochondrodysplasias cause short stature (dwarfism). Dwarfism is defined as an adult height of 4 feet 10 inches (147 centimeters) or shorter in both men and women. Some osteochondrodysplasias cause more shortening of the limbs than the trunk (short-limbed dwarfism), whereas others cause more shortening of the trunk than the limbs. The most common and best-known type of short-limbed dwarfism is called achondroplasia. Children and adults with achondroplasia often have Bowlegs , a bulky forehead, an unusually shaped nose (saddle nose), and an arched back. Sometimes joints do not develop their full range of motion. There is a lethal form of short-limbed dwarfism called thanatophoric dysplasia that causes severe deformities of the chest and respiratory failure in newborns, which results in death. 