Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to isodicentric chromosome 15 syndrome ?
    ### Response:
    Isodicentric chromosome 15 syndrome results from the presence of an abnormal extra chromosome, called an isodicentric chromosome 15, in each cell. An isodicentric chromosome contains mirror-image segments of genetic material and has two constriction points (centromeres), rather than one centromere as in normal chromosomes.
    