Identification of mutation in a candidate gene for hereditary multiple exostoses type II

Objectives To identify possible mutations in our previously cloned candidat e gene for hereditary multiple exostoses type II (EXT2) in affected members of EXT families so as to confirm that it is the disease-causing gene. Methods The mutation was detected first by single strand conformational pol ymorphism (SSCP) of all coding exons of the candidate gene and then by sequ encing analysis. Results After analyzing 37 patients from 20 Chinese EXT families by SSCP an d DNA sequencing analysis, one 2-bp insertion mutation was identified in th is candidate gene in affected members of an EXT family. This mutation resul ted in the frameshift and generated a truncated gene product consisting of 105 amino acids. Conclusions The identification of the mutation in the candidate gene indica tes that this novel gene is responsible for EXT2 (one of the disease-causin g gene of EXT).