Study on EXT gene mutation of a pedigree with hereditary multiple exostoses

Objective To investigate the EXT gene mutation in a pedigree with hereditary multiple exostoses(HME).Methods All exons and their flank sequences in EXT1 and EXT2 genes obtained from proband’s genomic DNA were amplified by PCR,the PCR products were then purified and directly sequenced.Results A heterozygous mutation,1564-7delC was found in proband’s EXT1 gene.The mutation caused a frameshift from 522-amino acid site and a premature terminating code was introduced at 546-amino acid site,producing a truncated protein.Family pedigree study showed that this mutation was come from proband’s mother.No variant was found in EXT2 gene.Conclusions 1564-7delC heterozygous mutation in EXT1 gene is the molecular mechanism of developing HME in this pedigree.