Isodicentric 15 Duplication
Isodicentric chromosome 15, abbreviated idic(15), is diagnosed in individuals who have 47 chromosomes (or sometimes more) instead of the typical 46 chromosomes. The extra chromosome is made up of a portion of chromosome 15 that has been duplicated and “inverted,” so that there are two copies of part of chromosome 15q attached to one another that appear to be mirror images. (dup15q.org)