2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-#NUM!

Pdf Summary

This study discusses two cases of absent ductus venosus (ADV) as a prenatal ultrasound finding of Noonan syndrome. Noonan syndrome is a genetic condition with various clinical manifestations. The prenatal ultrasound findings of Noonan syndrome include thickened nuchal translucency, pleural effusions, and fetal hydrops. Prenatal diagnosis of Noonan syndrome through techniques like chorionic villus sampling or amniocentesis is important for guiding fetal and neonatal evaluation, genetic counseling, and pregnancy planning.<br /><br />In case #1, a 34-year-old woman with a singleton pregnancy had a thickened nuchal translucency at 12 weeks. A prenatal ultrasound at 28 weeks diagnosed absent ductus venosus and severe polyhydramnios. The fetus developed bilateral pleural effusions, and multiple amnioreduction and fetal thoracentesis procedures were performed. Delivery occurred at 31 weeks due to worsening hydrops. The neonate exhibited features of neck webbing, low-set ears, and depressed nasal bridge. Genetic testing revealed a maternally-inherited heterozygous pathogenic variant of the PTPN11 gene.<br /><br />In case #2, a 31-year-old woman with a twin pregnancy had absent ductus venosus identified in one twin at 22 weeks. The patient declined diagnostic testing. At 30 weeks, the affected fetus developed bilateral pleural effusions, and at 32 weeks, delivery was necessary due to worsening hydrops. The neonate showed features of low-set ears and neck webbing. Genetic testing identified a heterozygous pathogenic variant of the PTPN11 gene.<br /><br />The absence of the ductus venosus can be diagnosed through prenatal ultrasound and should prompt further diagnostic testing for Noonan syndrome. Prenatal diagnosis is essential for directing fetal and neonatal evaluation and providing genetic counseling. Genetic testing can also assist in counseling for current and future pregnancy planning.

Asset Subtitle

Presenting Author - Jennifer Kidd, MD, MPH, FACOG; Co-Author - Jennifer Kidd, MD, MPH, FACOG; Co-Author - Meghan McGath, MS; Co-Author - Berrin Monteleone, MD; Co-Author - Patricia Rekawek, MD; Co-Author - Martin Chavez, MD;

Meta Tag

Fetal Pathology

Genetic Testing

Prenatal Diagnosis

Ultrasound

Co-Author Jennifer Kidd, MD, MPH, FACOG

Co-Author Meghan McGath, MS

Co-Author Berrin Monteleone, MD

Co-Author Patricia Rekawek, MD

Co-Author Martin Chavez, MD

Presenting Author Jennifer Kidd, MD, MPH, FACOG

Keywords

Noonan syndrome

absent ductus venosus

prenatal ultrasound

thickened nuchal translucency

pleural effusions

fetal hydrops

chorionic villus sampling

amniocentesis

genetic counseling

pregnancy planning