Achondroplasia

Achondroplasia ( /əˌkɒndrɵˈpleɪziə/) is a common cause of dwarfism. It occurs as a sporadic mutation in approximately 75% of cases (associated with advanced paternal age) or may be inherited as an autosomal dominant genetic disorder.

Achondroplastic dwarfs have short stature, with an average adult height of 131 centimeters (51.5 inches) for males and 123 centimeters (48.4 inches) for females. Achondroplastic adults are known to be as short as 62.8 cm (24.7 inches). The disorder itself is caused by a change in the DNA for fibroblast growth factor receptor 3 (FGFR3), which causes an abnormality of cartilage formation. If both parents of a child have achondroplasia, and both parents pass on the mutant gene, then it is very unlikely that the homozygous child will live past a few months of its life. The prevalence is approximately 1 in 25,000.