ABSTRACT
Objective To detect and analyze the mutation of fibroblast growth factor receptor 3(FGFR3) gene among a family with congenital achondroplasia(ACH).Methods Six blood samples of family member in this pedigree were cellected according to the informed consent process for genetic research,and 2 unralted healthy human blood sample were taken as controls.The mutation at nucleotide position 1 138 on FGFR3 gene was detected by using Polymerase chain reaction and single-strand conformation polymorphism(PCR-SSCP)and polyme-rase chain reaction and restriction endonuclease technology(PCR-RFLP) methods.Results Using PCR-SSCP method firstly,only the proband with ACH and his father in this family had the same abnormal band.The amplified products including 1 138 loci on FGFR3 gene further was analyzed by Sfe Ⅰ digestion,3 fragments including 164 bp,109 bp and 55 bp were detected in the proband and his father again,and the other members in the family and 2 controls just showed 164 bp band.It indicated that just 2 patients (proband and his father) showed heterozygous G→A transition mutation at nucleotide position 1 138 on the FGFR3 gene.The amplified products at 1 138 loci was also detected by MspⅠ digestion,just 1 band was observed in all members in this family and 2 controls.It showed that there was no G→C substitution at nucleotide position 1 138.Conclusions The G→A transition mutation at nucleotide position 1 138 in transmembrane domain of FGFR3 gene may be the main cause of achondroplasia in this family.In this pedigree,the proband showed's father a de novo mutation which was transferred to his child again.