Department of Reproduction and Genetics,Jinling Hospital,Clinical School of Medical College,Nanjing University,Nanjing 210002,China
Abstract:
In the case of a previous offspring with trisomy 21, recurrence risk for Down syndrome is about 1%. It may be due to chance, but the possibility of germline mosaicism for trisomy 21 in one of the parents has important implications for the recurrence. Here we report a young healthy mother, who has a second pregnancy of trisomy 21.