目的　对临床怀疑染色体病或需排除染色体畸变的患儿进行细胞遗传学染色体检查 ,以探讨小儿先天异常与染色体异常之间的关系。方法　对小儿先天异常就诊者取外周血 ,37℃培养 ,常规制片 ,G显带 ,行染色体分析。结果　共检查 2 99例小儿先天异常患者的染色体 ,其中因智力低下就诊者 2 2 5例。共发现异常核型 12 9例 ,占 4 3.14 % ,其中常染色体数目异常 10 2例 ,嵌合体 4例 ,常染色体结构异常 10例 ,性染色体数目异常 4例 ,染色体与社会性别不符 7例。结论　染色体畸变是小儿先天异常特别是小儿智力低下的主要原因之一 Objective To investigate the relationship between chromosomal abnormalities and chromosomal abnormalities in children with suspected chromosomal diseases or with chromosomal aberrations. Methods Peripheral blood was collected from children with congenital anomalies, cultured at 37 ℃, routinely prepared, G - banding, and analyzed by chromosome. Results A total of 2 99 cases of children with congenital anomalies were examined for chromosomes, of which 225 cases were diagnosed due to mental retardation. A total of 129 abnormal karyotypes were detected, accounting for 4. 3.14%. There were 102 cases of an autosomal abnormality, 4 cases of chimerism, 10 cases of an autosomal abnormality, 4 cases of abnormal sex chromosome number, and 7 cases of chromosomal mismatch with gender. Conclusion Chromosome aberration is one of the main causes of congenital abnormalities in children, especially in children with mental retardation