神经系统异常胎儿的染色体微阵列分析

Prenatal diagnosis of central nervous system anomalies by array-based comparative genomic hybridization

目的探讨胎儿神经系统畸形在染色体异常产前诊断的价值,为临床咨询提供指导。方法对入选的131例产前超声诊断为神经系统畸形且行产前介入性诊断的胎儿,回顾其染色体核型分析及aCGH结果。根据是否合并神经系统外畸形将研究对象分为2组:单纯性神经系统畸形组(84例)及合并神经系统外畸形组(47例)。结果单纯性神经系统畸形组和合并神经系统外畸形组染色体G显带阳性率分别为2/84(2.4%)和15/47(31.9%),aCGH异常率分别为5/84(5.9%)和19/47(40.4%)。合并神经系统外畸形组染色体G显带及aCGH异常检出率均显著高于单纯性神经系统畸形组。本研究染色体异常的研究对象中,不同的神经系统畸形类型中阳性率最高的是Dandy-Walker综合征,为55.6%(5/9),其次为全前脑,为50.0%(4/8)。结论胎儿神经系统畸形染色体异常率及aCGH异常率增高,是产前诊断的重要指征。当合并其他系统畸形时,染色体异常率及aCGH异常率显著升高。当产前发现神经系统畸形时,都应建议其产前诊断,行核型分析及aCGH检查。

Objective The aims of this study were to evaluate the contribution of chromosomal microarray analysis （CMA） in the prenatal diagnosis of fetuses with central nervous system （CNS） anomalies. Method A retrospective study of the karyotypes and aCGH outcomes of selected 131 cases with CNS anomalies by invasive prenatal procedures. The subiects were divided into two groups according to ultrasound anomalies： group I ： 84 cases isolated CNS anomalies, group II： 47 cases accompanied with other anomalies. Results The result showed that abnormal karyotypes were detected in 17 （13. 0%） fetuses. Fetuses with CNS malformations plus other ultrasound anomalies had a significantly higher rate than those with isolated CNS anomalies （31.9% versus 2.4%, P〈0.05）There were 24 （18.3%） fetuses detected with pathogenic aCGH results. Fetuses with CNS malformations plus other ultrasound anomalies had a significantly higher rate of pathogenic results than those with isolated CNS anomalies （40. 4%versus 5.9 %, P〈 0.05）. Pathogenic chromosomal abnormality were detected most frequently in fetuses with Dandy-Walker syndrome （5/9, 55.6%） when compared with other types of neural malformations, and holoprosencephaly （4/8, 50.0%） ranked the second. Conclusions Karyotype analysis and aCGH should be considered as prenatal diagnosis in fetuses with CNS malformations, particularly when other ultrasound anomalies are detected, aCGH is valuable in prenatal genetic diagnosis of fetuses with CNS anomalies.