ASXL1-related Bohring-Optiz syndrome complicated by persistent neonatal pulmonary hypertension and abnormal alveoli formation.

Bohring-Opitz syndrome (BOS) is a rare disease with a characteristic facial appearance and limb position. This report describes a case of BOS complicated by persistent pulmonary hypertension of the newborn (PPHN) and formation of abnormal alveoli that was confirmed by autopsy. A female neonate was born by cesarean section at 37 weeks and 2 days of gestation and found to have a nevus flammeus, exophthalmos, abnormal palate, retraction of the mandible, and a posture characteristic of BOS. The patients had severe PPHN requiring inhalation of nitric oxide. Genetic testing revealed a de novo frameshift variant in ASXL1. Autopsy revealed that the lung was at the saccular stage, equivalent to 28-34 weeks of gestation. This is the first report to present pathological evidence of immaturity of the lung that may be associated with PPHN in a patient with BOS caused by a variant in ASXL1.