Identification of Mutations in the Gene Encoding the Fibroblast Growth Factor Receptor 3 in Japanese Patients with Achondroplasia

Abstract We examined mutations in the gene encoding the fibroblast growth factor receptor 3 (FGFR3) in nine Japanese patients diagnosed as typical achondroplasia (ACH) and two patients with hypochondroplasia (HCH) using polymerase chain reaction (PCR) coupled with direct sequencing. In our present cases, equivalent to previously reported cases in France and the U. S. A., all mutations affected with ACH were the same nucleotide change, a G→A transition at position 1,138, resulting in the substitution of arginine for glycine at position 380 of the mature protein. Therefore, the gene mutation of ACH indicates no significant differences between the Caucasian and the Japanese. On the other hand, PCR products from genomic DNA of HCH did not show the same mutation.