<prompt> Down syndrome, All are seen except -t14:21Trisomyt11:14t15:21  <response>: Ans. is c i.e., t 11:14 Ref: Nelson 17the Chapter 18o In 95 of cases of Down syndrome-trisomy of 21.o Extra chromosome is of maternal in origin,o 1 have mosaic with some all have 46 chromosome,o 4 have robertsonian translocation.t13:21t14:21t15:21o Very rarely long arm of chromosome 21 is triplicate Partial trisomy. 