how common is Achondroplasia
Skeletal dysplasias are conditions of abnormal bone growth that cause disproportionate dwarfism. They include: Achondroplasia. The most common form of dwarfism, achondroplasia occurs in about one out of 26,000 to 40,000 babies and is evident at birth.People with achondroplasia have a relatively long trunk and shortened upper parts of their arms and legs.Other features of achondroplasia include: 1  a large head with a prominent forehead.keletal dysplasias are conditions of abnormal bone growth that cause disproportionate dwarfism. They include: Achondroplasia. The most common form of dwarfism, achondroplasia occurs in about one out of 26,000 to 40,000 babies and is evident at birth.