摘要本文报道了1例产前诊断的ZTTK综合征胎儿。孕妇因配偶染色体平衡易位，行胚胎植入前遗传学诊断。孕18周 +取羊水细胞行染色体核型分析及基因组拷贝数变异测序均未发现异常。孕23周 +5及孕26周 +3超声检查显示严重胎儿生长受限、小脑发育异常、骶骨及尾骨显示欠清、脊柱裂，孕23周 +6胎儿颅脑MRI显示胎儿双侧小脑半球体积小，大枕大池。对胎儿及其父母行全外显子组测序，结果显示胎儿 SON 基因3号外显子存在1个杂合变异c.2092delG（p.Glu698fs*4），父母不存在该变异，为新发变异；该位点为致病性，关联疾病为ZTTK综合征。经遗传咨询，孕妇及家属选择终止妊娠。

abstractsThis article reported the prenatal diagnosis of a fetus with ZTTK syndrome. A pregnant woman underwent preimplantation genetic diagnosis because her partner carried a balanced chromosomal translocation. Chromosomal karyotype analysis and copy number variation sequencing (CNV-seq) performed on amniocytes collected at 18 + weeks of gestation revealed no abnormalities. Ultrasonography performed at 23 +5 and 26 +3 weeks of gestation revealed severe fetal growth restriction, cerebellar dysplasia, poorly visualized sacrum and coccyx, and spina bifida. MRI of the fetal brain showed that the bilateral cerebellar hemispheres of the fetus were small and the cisterna magna was large at 23 +6 weeks of gestation. Whole exome sequencing in the pedigree identified a heterozygous variant c.2092delG (p.Glu698fs*4) in the exon 3 of the fetal SON gene, which was not inherited from the parents and proved to be a de novo mutation. Mutations in the locus are pathogenic, causing ZTTK syndrome. After genetic counseling, the pregnant woman and her family chose to terminate the pregnancy.