Below is an instruction from Human. Write a response.
    ### Instruction:
    Is Rett syndrome inherited ?
    ### Response:
    In more than 99 percent of people with Rett syndrome, there is no history of the disorder in their family. Many of these cases result from new mutations in the MECP2 gene.  A few families with more than one affected family member have been described. These cases helped researchers determine that classic Rett syndrome and variants caused by MECP2 gene mutations have an X-linked dominant pattern of inheritance.
    