Prenatal Diagnosis Of Holoprosencephaly With Proboscis And Cyclopia Caused By Monosomy 18p Resulting From Unbalanced Whole-Arm Translocation Of 18;21

A case of holoprosencephaly (HPE) with proboscis, fused eyes in one orbit, and cyclopia was diagnosed by fetal ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). Ultrasonographic examination at 28 weeks of gestation showed fusion of the frontal part of the brain and ventricular dilation. Subsequent CT and MRI examinations confirmed this anomaly as alobar HPE. Amniocentesis followed by chromosome analysis demonstrated karyotype as de novo 45, XY, der (18;21)(q10;q10), with deletion of a short arm of chromosome 18. The pregnancy ended in a premature delivery of a male neonate weighing 1716 g at 34 weeks. Macroscopically, there were mid-frontal proboscis and single orbit with two eyes without normal nasal structures. He died 1 h after birth.