Editing Hereditary multiple exostoses (section)

==Diagnosis==
The diagnosis of HMO is based upon establishing an accurate correlation between the above-mentioned clinical features and the characteristic radiographic features. Family history can provide an important clue to the diagnosis. This is supplemented by testing for the two genes in which pathogenic variants are known to cause HMO namely EXT1 and EXT2. A combination of sequence analysis and deletion analysis of the entire coding regions of both EXT1 and EXT2 detects pathogenic variants in 70–95% of affected individuals.<ref name="Genereviews"/><ref name="Alvarez2007"/> The hallmark of radiographic diagnosis is the presence of osteochondromas at the metaphyseal ends of long bones in which the cortex and medulla of the osteochondroma represent a continuous extension of  the host bone. This is readily demonstrable in radiographs of the knees.<ref name=Genereviews/><ref name="elsobky2018"/>