Causes of Achondroplasia
Achondroplasia results from specific changes (mutations) of a gene known as fibroblast growth factor receptor 3 (FGFR3).

For most patients, there is no apparent family history of the condition. Increased age of the father (advanced paternal age) may be a contributing factor in cases of sporadic achondroplasia.

Less commonly, familial cases of achondroplasia follow an autosomal dominant pattern of inheritance. Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary to cause a particular disorder. The abnormal gene can be inherited from either parent or can be the result of a mutated (changed) gene in the affected individual. The risk of passing the abnormal gene from an affected parent to an offspring is 50% for each pregnancy. The risk is the same for males and females.