Chromosomal variations (aberrations) are of interest for MIM/OMIM for several reasons. These include the role of specific genes deleted or duplicated in aneuploid states in determining phenotype; see Down syndrome (MIM #190685), Wolf-Hirschhorn syndrome (MIM #194190), cri-du-chat syndrome (MIM #123450), Emanuel syndrome (MIM #609029), 22q11.2 deletion syndrome (MIM #188400), Jacobsen syndrome (MIM #147791), 9q subtelomeric deletion syndrome (MIM #610253), and others.