Hereditary multiple exostoses is inherited in an autosomal dominant disease.
Most individuals with MHE / MO / HME have a parent who also has this condition, however, approximately 10% of individuals with
MHE / MO / HME have this condition as a result of a spontaneous mutation are thus the first person in their family to be
affected.
Genetic Testing of the EXT1 and EXT2 genes is available on a clinical basis. Please read Genetic Guides and
laboratories information located near the bottom of this website page.
There are two known genes that cause this disease EXT1 located on chromosome 8q23-q24 and EXT2 located on chromosome
11p11-p12. Approximately 60 to 70 %are located EXT1 gene and 20 to 30% are located EXT2 mutation. In 10 to 20% of the
patients, no mutation is found.
Offspring of an affected individual have a 50% risk of inheriting the altered gene for hereditary multiple exostoses.