The symptoms described (small round head, furrowed tongue, partially open mouth, broad palm with characteristic palm crease, and retarded development) are strictly characteristic of Down’s syndrome . This genetic disorder is caused by the presence of an additional copy of chromosome number 21 (aneuploidy), known as trisomy of 21 . Option 1 (47, XXY) refers to Klinefelter’s Syndrome and Option 2 (45, XO) refers to Turner’s Syndrome.