Early neonatal death due to prenatally undiagnosed congenital subglottic stenosis in Noonan syndrome

INTRODUCTION: Congenital subglottic stenosis is a rare malformation of the laryngeal airway. In its severe forms, it can result in immediate neonatal respiratory failure and death if not managed emergently at birth. CASE PRESENTATION: A pregnant woman, whose fetus was suspected of having Noonan syndrome, underwent a cesarean delivery. Notably, subglottic stenosis was not detected on prenatal imaging. The neonate exhibited immediate and severe respiratory distress, and upper airway obstruction was diagnosed during neonatal resuscitation, leading to failed intubation and subsequent neonatal demise. The post-mortem examination revealed cartilaginous subglottic stenosis and type C tracheoesophageal (TE) fistula. Exome sequencing identified a de novo, c.923 A>G, PTPN11 pathogenic variant. CONCLUSION: The pitfalls in prenatal diagnosis and genetic counseling could raise awareness of possible lethal upper airway obstruction in Noonan syndrome patients. Comprehensive prenatal evaluation and diagnosis are critical to ensuring appropriate neonatal resuscitation.