Severe Neonatal Cardiopulmonary Failure with Suspected RASopathy: A Case Report

Neonatal cardiopulmonary failure may reflect underlying genetic disorders, including RASopathies caused by dysregulation of the RAS-MAPK signaling pathway. We report a late preterm neonate with severe cardiopulmonary compromise in whom whole-exome sequencing identified a heterozygous RAF1 missense variant (c.991A>T; p.Arg331Trp), along with a ZIC3 variant. The RAF1 variant has not been previously described and may represent an expanded phenotypic spectrum of RAF1-associated disease. This case underscores the challenges of interpreting novel genomic variants in critically ill neonates and highlights the importance of correlating molecular findings with clinical presentation. Reporting such rare variants is essential to refine genotype-phenotype relationships and improve diagnostic accuracy in neonatal RASopathies.