This collection consists of phenotypic cohort definitions for patients with conditions that are present at birth, inherited through genetic transmission, or arise in the neonatal period. These diseases may affect nearly any organ system and can range from structural malformations (e.g., congenital heart defects) to metabolic disorders (e.g., phenylketonuria) or genetic syndromes (e.g., Down syndrome). Phenotype logic in this category may use age at diagnosis, genetic testing results, newborn screening outcomes, family history, or relevant diagnostic codes flagged during the perinatal or neonatal period. Additional logic may incorporate birth registry data or growth/developmental milestones. Example phenotypes include “Neonatal Sepsis,” defined by early-life infection diagnoses and antibiotic treatment, and “Cystic Fibrosis,” which might be captured using genetic testing data, elevated sweat chloride levels, or confirmed diagnosis by a pediatric pulmonologist.