what gene of achondroplasia is affected by it
Genetics. 1  Achondroplasia is a single gene disorder caused by mutations in the FGFR3 gene on chromosome 4. 2  Two different mutations in the FGFR3 gene cause more than 99 per cent of cases of achondroplasia. 3  It is a dominant genetic disease so only one copy of the FGFR3 gene needs to be mutated for symptoms to develop.chondroplasia is a genetic disorder affecting bone development that results in short-limb dwarfism. 1  Achondroplasia is the most common form of short-limb dwarfism, a disorder in which bone tissue does not develop properly, especially the long bones of the arms and legs.