This GCEP will seek to quantify the evidence supporting/not supporting the genes in which variants are purported to cause non-immune hydrops (NIHF), stillbirth, and additional severe prenatal phenotypes. We are pleased to be funded in this year’s cycle of U24 grants. To create a preliminary gene candidate list for NIFH curation, we found 151 genes with reported relationships with NIHF from a review of 3 frequently used, commercially available NIHF gene panels (52- 130 genes), the PanelApp from Genomics England (89 genes), and the NIHF repository of 123 sequenced Last updated: Jan 20, 2021 (v.5) cases at UCSF (provided by expert panel member Teresa Sparks, MD). To create a preliminary gene candidate list for stillbirth curation, we found 221 genes with reported relationships with stillbirth through an exhaustive search of OMIM identifying all genes associated with stillbirth, our own experience sequencing 246 such cases, 19 a review of stillbirths in The Fetal Anomalies Panel developed by the PAGE consortium, 6 and 94 cardiac-related sudden death-susceptibility genes reported in a series of stillbirths.