A new case of Casamassima-Morton-Nance (CMN) syndrome presenting prenatally as VACTERL association

Abstract

Abstract Casamassima-Morton-Nance (CMN) syndrome (OMIM 271520) has clinical overlap with spondylocostal dysostosis and Vertebral, Anorectal, Cardiac, Tracheo-Esophageal, Radial/Renal, Limb (VACTERL) association but with consistent features of anal and urogenital abnormalities, particularly ambiguous genitalia. Since the original report, it has become clear that the combination of vertebral segmentation abnormalities, rib abnormalities, and urogenital anomalies may enable prenatal diagnosis of CMN by ultrasound. CMN syndrome is an important diagnosis to consider prenatally because of the generally poor prognosis compared to the more common VACTERL association. Here we present the seventh reported case of CMN syndrome. Prenatally presenting features of multiple segmentation anomalies within the spine, a left multi-cystic dysplastic kidney, marked pelvicaliectasis with abnormal renal parenchyma and a small stomach were suggestive of VACTERL association. There was severe oligohydramnios. Termination of pregnancy was performed at 22 weeks gestation and autopsy revealed dysmorphic coarse facial features, marked scoliosis, bilateral talipes, ambiguous external genitalia, and anal atresia. These features were highly suggestive of CMN syndrome. The important discriminating feature of ambiguous genitalia was not apparent on the prenatal ultrasound in this case because of severe oligohydramnios but we suggest that careful prenatal ultrasound assessment of the genitalia in cases of suspected VACTERL is important in differentiating these two conditions.