It is not yet known how common 22q11.2 Duplication is. Because there are likely so many individuals who remain undiagnosed, it is hard for doctors to estimate the prevalence of this syndrome. Best estimates fall in the range of 1/700 live births. Click here to see more.
22q11.2 Duplication Syndrome is not detectable by routine genetic testing (called karyotyping.) Most individuals with 22q11.2 duplication are identified either by something called array genomic hybridization (array GH) testing or by multiplex ligation-dependent probe amplification (MLPA) testing for 22q11.2 deletion syndrome. Both of these tests are performed with blood work but can be diagnosed in pregnancy using cells from the placenta or the amniotic fluid.
About 70 percent of individuals with the duplication inherit it from one of their parents. In other cases, the duplication is not inherited and occurs as a random event during the formation of the child. Any person with the duplication has a 50% chance of having a child with the same duplication.