G显带联合Array-CGH技术在产前超声异常胎儿诊断中的应用研究

摘要

Objective To use combined comparative genome hybridization (array-CGH) and conventional karyotype analysis to study the relationship between ultrasonographic abnormalities of fetuses and chromosomal aberrations.Methods One hundred twenty two fetuses with ultrasonographic abnormalities in middle and late trimesters suspected with chromosomal abnormalities were collected between March 2012 and February 2013.Results The pregnant women had an average age of 31 yr (22-38),among whom 35 were above the age of 35.The average gestational age was 27+5 weeks (18～37 weeks),and the most common abnormal findings have involved heart,central nervous system and bones.Multiple malformations were found in 49 cases.The success rate of the combined methods was 100％.In 24 (19.7％) of the cases,a chromosomal abnormality was detected.Among all cases,16 (13.1％) were detected by the combined method (12.3 ％).Seventeen cases (13.9 ％) of chromosomal abnormalities and 4 cases (3.3％) of polymorphic variation were detected by karyotype analysis,and 23 cases (8.9％) of abnormalities were detected by array-CGH.Meanwhile,7 cases (5.7 ％) of abnormalities were detected by array-CGH,but the results of karyotype analysis were normal.One case (0.8％) with low level of chromosome chimerism detected by the karyotype analysis was missed by array-CGH.Conclusion The results suggested that multiple congenital deformity of the fetus has a strong correlation with chromosomal abnormalities.For fetuses with ultrasonographic abnormalities,array-CGH can improve the detection sensitivity of the chromosomal disease.%目的 探讨孕中晚期超声异常的胎儿与染色体异常的关系以及微阵列比较基因组杂交技术(array comparative genome hybridization,array-CGH)在产前诊断中的应用价值.方法 收集因各种原因错过孕早期诊断、并在中晚期妊娠发现超声异常并怀疑染色体异常的高风险胎儿122例,同时采用常规核型分析和array-CGH对胎儿进行脐血染色体分析.结果 孕妇平均年龄为31岁(22～38岁),其中年龄≥35岁的孕妇17人,诊断时平均孕龄为27+5周(18～37周),最常见的B超异常为心脏、中枢神经系统和骨骼方面.B超显示多发畸形的胎儿有49例,单一畸形的胎儿有73例.两种方法联合检测成功率为100％.共检出染色体异常核型24例,异常率为19.7％.其中两种技术均检测到的16例(占13.1％).核型分析共检出异常17例,其中有3例array-CGH检测到额外的基因拷贝数变异.多态性变异4例.array-CGH分析共检出异常23例,核型分析提示正常、但array-CGH检测到异常有7例.核型分析提示异常染色体低比例嵌合、但array-CGH显示正常有1例.结论 胎儿多发畸形与染色体异常明显相关.对于产前超声异常的胎儿,array-CGH技术能在分子细胞遗传的水平上提高染色体病检测的敏感性.