Fetal Presentation of MYRF-Related Cardiac Urogenital Syndrome: An Emerging and Challenging Prenatal Diagnosis

Purpose: MYRF-related cardiac-urogenital syndrome (MYRF-CUGS) is a rare condition associated with heterozygous MYRF variants. The description of MYRF-CUGS phenotype is mostly based on postnatal cases and 36 affected individuals have been published so far. We aim now to delineate the prenatal phenotype of MYRF-CUGS by reporting clinical data from fetuses and neonates with a pathogenic MYRF variant. Methods: Detailed radiographic, pathological, clinical, and molecular data from 12 prenatal cases were collected through an international collaborative study. Adding the five fetuses previously published, we were able to study a cohort of 17 cases. Results: Main ultrasound-accessible manifestations of MYRF-CUGS include congenital heart defects (13/17, 76%), congenital diaphragmatic hernia (10/17, 59%) and disorders of sexual differentiation in 46, XY fetuses (7/14; 50%). Postnatal examination and/or autopsy data highlighted additional birth defects and neurological findings with a large spectrum of severity. Molecular results revealed ten previously unpublished variants, one missense and nine predicted truncating variants (three frameshift, three nonsense and three splice site variants). Conclusion: We report the first prenatal cohort of MYRF-CUGS, allowing us to further characterize the variable expressivity of this rare disorder in fetuses. Severe congenital anomalies with a poor prognosis are more frequent than previously described in postnatal cases. Our data suggest that MYRF-CUGS is characterized by a recurrent recognizable malformative association, accessible to prenatal diagnosis, with a significant intrafamilial phenotypic variability making genetic counseling challenging.