22q11.2 Duplication Syndrome

22q11.2 duplication syndrome is a condition caused by an extra copy of a small piece of chromosome 22. The features of this condition vary widely, even among members of the same family. Affected individuals may have developmental delay, intellectual disability, slow growth leading to short stature, and weak muscle tone (hypotonia). Many people with the condition have no apparent physical or intellectual disabilities. It is inherited in an autosomal dominant manner, with about 70 percent of affected individuals inheriting the condition from a parent. In other cases it occurs as a de novo mutation (new genetic change) in an individual; however, individuals with a de novo mutation can can pass the duplication to their children. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.