Fig. 1.

The facial appearance, FISH results and array CGH profile for the patient. a Frontal and lateral view of the patient at the age of 5½ years displays some distinctive clinical features of DS including posterior plagiocephaly, flat face, epicanthus, upslanted palpebral fissures and anteverted nares. b FISH result on metaphase spreads and interphase preparation using a probe for DSCR on chromosome 21 (orange signals) and RB-1 as a control probe on chromosome 13 (green). The fluorescence signal on one chromosome 21 is stronger as compared to the signal on the other chromosome 21 (arrows). Three orange signals for chromosome 21 are visible on interphase nuclei. c Array CGH result (Agilent, 180 K array). Zoom view of the 2.56 Mb mosaic microduplication and gene content at 21q22.13q22.2 encompassing DYRK1A (red box) as duplicated candidate DSCR gene