B60-27 Clinical Diagnosis of Cerebrocostomandibular Syndrome Confirmed by Genetic Testing: A Case Report With Multidisciplinary Management

Cerebrocostomandibular syndrome (CCMS) is a rare congenital disorder characterized primarily by severe mandibular hypoplasia, posterior rib-gap defects and various degrees of cerebral maldevelopment. CCMS usually occurs as an isolated event within a family and demonstrates genetic heterogeneity, with both AR and AD patterns. These structural abnormalities lead to respiratory distress, upper airway obstruction, and decreased thoracic capacity needing early airway management and respiratory support. This is a very preterm neonate born with severe clinical features of CCMS, emphasizing the importance of early multidisciplinary intervention and the impact of thoracic and airway severity on overall prognosis. A 29 week and 2 day old female was born to a 29 year old G5P2113 mother via c-section.Pregnancy was complicated by preterm labor, premature rupture of membranes, and polyhydramnios. Infant had a prenatal diagnosis of severe micrognathia requiring stabilization via an Ex Utero Intrapartum Treatment procedure. A multidisciplinary team was present for stabilization included Pediatric ENT, Anesthesiology, and NICU. Birth weight was 1,066g with Apgar scores of 4, 5, 6. Physical exam remarkable for severe micrognathia, narrow thorax with cartilaginous ribs, and upper-extremity webbing at the elbows. The infant was also noted to have esophageal atresia, ASD, and a large PDA. She quickly developed severe pulmonary hypertension and respiratory failure, requiring high-frequency jet ventilation. Chest xray showed a very small thoracic cage with markedly reduced rib shadowing with severely hypoplastic ribs bilaterally, narrow, bell-shaped chest consistent with pulmonary hypoplasia and a replogle tube in the esophageal pouch. Genetic testing revealed a de novo heterozygous pathogenic variant in the SNRPB gene (c.155 + 310G>C), consistent with CCMS. Despite maximal ventilatory and pharmacologic support, the infant developed progressive pulmonary hypertension, anasarca, and worsening acid-base status. Following multidisciplinary discussions and shared decision-making, the family elected compassionate withdrawal of life-sustaining therapy on day 11 of life. CCMS is a rare congenital disorder with fewer than 100 cases reported caused by pathogenic variants in the SNRPB gene, leading to mandibular and thoracic malformations of variable severity. The association of severe micrognathia, non-ossified ribs, and reduced thoracic development produces critical airway obstruction and respiratory failure, resulting in high neonatal mortality. In our patient, a de novo SNRPB variant caused profound respiratory insufficiency refractory to maximal ventilatory support. This case emphasizes the importance of early prenatal recognition, multidisciplinary perinatal team, timely genetic confirmation to further guide counseling, medical management and support ethical decision making in the management of severe CCMS cases. This abstract is funded by: None