[A mutation 1633-26(C--A) in EXT1 gene causes multiple exostoses]

To study the gene mutation in a patient with multiple exostoses, identify the disease-causing gene mutation.Polymerase chain reaction and DNA sequencing were used to screen the EXT1 or EXT2 gene mutation, while mismatch primer amplification and restriction endonuclease digestion were performed to confirm the mutation.By DNA sequencing, a mutation in the seventh intron was detected and located at 26 bp of 3' splice site upstream in EXT1 gene, which was unreported before. Mismatch primer amplification and restriction fragment length polymorphism analysis suggested that this mutation was not detected in the normal control.The mutation 1633-26(C--A) may be the disease-causing mutation in this patient with multiple exostoses.