唐氏综合征(Down’s syndrome,DS)又称先天愚型、21-三体综合征,是一种最常见的伴有智力障碍的染色体疾病。新生儿中的发病率为1/800～1/600,但是约2/3的唐氏综合征患儿在妊娠早、中期自发流产和胎死宫内,因此实际发病率要比新生儿中的发病率高[1]。本病的主要特征是智能落后,生 Down’s syndrome (DS), also known as Down’s syndrome, 21-trisomy syndrome, is one of the most common chromosomal disorders associated with mental retardation. The incidence of neonates is 1 / 800-1 / 600, but about two-thirds of children with Down Syndrome spontaneously abortive and intrauterine pregnancy in early and middle third trimester of pregnancy, so the actual incidence of neonatal than High incidence [1]. The main features of the disease is smart backward, students