My grandson, born May 23, 2010, diagnosed shortly thereafter with Monosomy 21 Mosaic. He has a small portion of the 21st chromosome looped at the end of the tail. Doctor's in Toronto are not sure if it is useful to have this. All I've read is that there are no long term case studies on this rare disorder. Does anyone have anything to share about this disorder. He looks normal, nothing like I've seen on the internet. Currently has an enlarged heart, has trouble feeding and regurgitates his feed choking on it and having to be suctioned. He has gained weight from his 3 lb 3 oz birth, but it's up and down depending upon his digestion.