CDKL5 and atypical Rett syndrome: This included the duplication-triplication involving PDHA1 (Family 41, described below), a participant with three interlinked duplications involving KDM6A (Family 31), and a rare 721-kb duplication in a female with suspected Rett syndrome (Family 29), which was assumed to be a tandem event but which the sequence data show has been inserted into CDKL5.