[Prenatal diagnosis and genetic analysis of two fetuses with paternally derived 17q12 microdeletions]

To reported on two fetuses diagnosed with 17q12 microdeletion syndrome.

The two fetuses were respectively found to have renal abnormalities and polyhydramnios upon second and third trimester ultrasonography. Umbilical cord blood of the first fetus and amniotic fluid of the second fetus were subjected to single nucleotide polymorphism array (SNP-array) analysis. After 17q12 microdeletion was found in the first fetus, SNP-array was carried out on peripheral blood samples of the parents to determine its origin. With the medical history of the parents taken into consideration, the father underwent high-throughput sequencing for 565 urinary system-related genes to exclude pathogenic or likely pathogenic variants associated with congenital malformations of the urinary and reproductive systems.

In both fetuses, SNP-array has revealed a 1.42 Mb deletion at 17q12, or arr[hg19]17q12 (34 822 465-36 243 365) × 1. In both cases the microdeletion was inherited from the father, in whom no urinary disease-related pathogenic or likely pathogenic variants was identified.

Paternally derived 17q12 microdeletions probably underlay the genetic etiology of the two fetuses with renal ultrasound abnormalities and polyhydramnios. SNP-array can enable the diagnosis and facilitate genetic counseling and prenatal diagnosis for the families.