Short rib-polydactyly syndrome (Saldino-Noonan type) undetected by standard prenatal genetic testing

Abstract

Short rib-polydactyly syndrome (SRPS) is an extremely rare lethal skeletal dysplasia characterized by organ abnormalities, polydactyly, shortened tubular bones and a constricted thoracic cage [Saldino RM. Lethal short-limbed dwarfism: achondrogenesis and thanatophoric dwarfism. Am J Roentgenol. 1971;112:185-97]. In this case, we describe a neonate born with Type I SRPS (Saldino-Noonan type). Prenatal ultrasounds were suspicious for skeletal dysplasia, but prenatal genetic testing was negative. Postnatally, the infant was found to have severely hypoplastic lungs, a large patent ductus arteriosus, hydrops fetalis, polydactyly and a saddle nose. Postnatal DNA sequencing confirmed the diagnosis of SRPS and revealed a compound heterogeneous mutation in a gene involved in primary cilia synthesis. Ultimately, the infant was withdrawn from life support at 7 days due to severe respiratory decompensation from the lung hypoplasia.