新发染色体异常是指双亲任何一方体细胞中都不存在的染色体畸变[1],是导致新生儿出生缺陷的一个重要原因。产前诊断中常见的新发染色体异常包括平衡性和非平衡性,这关系到妊娠结局和胎儿出生后表型,应严格区分。然而这种传统定义的平衡性染色体结构异常实际上可能是非平衡结构畸变,可导致异常表型的发生,如Giardino[2]和De Gregori[3]等通过FISH或比较基因组杂交技术已证实。1非平衡性新发染色体有文献指出,在产前诊断中新发的非平衡性染色体异常胎儿大都存在着明显的结构畸形,而且表型可能与非平衡片段的长度有关,长度越长所携带的基因数量可能就越多,所影响的功能就越大[4],常见的非平衡性新发染色体异常主要见于:缺失、重复以及新发标记染色体等。染色体缺失:是指染色体某处发生断裂后其断片未与原 New chromosomal abnormalities refer to chromosomal aberrations that do not occur in somatic cells of either parent [1] and are an important cause of birth defects in newborns. Neonatal chromosomal abnormalities common in prenatal diagnosis include the balance and non-equilibrium, which is related to the pregnancy outcome and phenotype after birth, should be strictly distinguished. However, this traditional definition of balanced chromosomal structural abnormalities may actually be unbalanced structural aberrations leading to abnormal phenotypes as demonstrated by FISH or comparative genomic hybridization techniques by Giardino [2] and De Gregori [3]. Unbalanced neo-chromosomal literature, the literature pointed out that in prenatal diagnosis of unbalanced chromosomal abnormalities mostly exist obvious structural abnormalities, and the phenotype may be related to the length of unbalanced fragments, the longer the length of the carrying The more the number of genes may affect the greater the function [4], the common unbalanced new chromosomal abnormalities mainly found in: deletion, duplication and new marker chromosomes. Chromosome loss: refers to the chromosome somewhere after the break did not fragment with the original