OBJECTIVE: To study the gene mutation of Chinese patients with 
achondroplasia(ACH) and to set up a simple and rapid molecular diagnostic method 
to differentiate ACH from other similar genetic dwarfism.
METHODS: The specific fragment of fibroblast growth factor receptor 3(FGFR3) 
transmembrane domain was amplified from dried blood spots of 21 patients with 
ACH and 6 suspicious patients with ACH by polymerase chain reaction, then 
mutation was screened and detected by restrictive enzyme analysis, single strand 
conformation polymorphism(SSCP) and denaturing gradient gel 
electrophoresis(DGGE).
RESULTS: One out of 6 suspicious cases was ACH and 5 were 
pseudoachondroplasia(PSACH). Twenty-one out of 22 patients with ACH bore a G to 
A transition at nucleotide 1138 and 1 bore a G to C transversion at this same 
position.
CONCLUSION: The nucleotide 1138 of FGFR3 gene is also the hotspot of mutation in 
Chinese patients with ACH. A simple and rapid molecular diagnostic method has 
been set up to differentiate ACH from other similar genetic dwarfism.