what is mosaic down syndrome
Mosaic Down Syndrome occurs when you have some cells with the normal two copies of chromosome 21 and some cells with an extra copy of chromosome 21.When this occurs, there is a mixture of two types of cells.Mosaic Down Syndrome occurs in only 1-2 percent of people with Down Syndrome, and there is a wide range in the level of severity of the impairment.hen this occurs, there is a mixture of two types of cells. Mosaic Down Syndrome occurs in only 1-2 percent of people with Down Syndrome, and there is a wide range in the level of severity of the impairment.