Prenatal diagnosis of fetal ZTTK syndrome: a case report / 中华围产医学杂志

ABSTRACT

This 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.