Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) 22q11.2 duplication syndrome ?
    ### Response:
    22q11.2 duplication syndrome is a condition caused by an extra copy of a small piece of chromosome 22 which contains about 30 to 40 genes. The features of this condition vary widely, even among members of the same family (intrafamilial variability). Affected individuals may have intellectual or learning disability, developmental delay, slow growth leading to short stature, and weak muscle tone (hypotonia).
    