Demographic, Metabolic, and Genomic Description of Neonates With Severe Hyperbilirubinemia

Inclusion Criteria: Case * Documentation of informed consent. * Gestational age greater than or equal to 37 weeks. * Birth weight greater than or equal to 2000 grams. * At least one serum bilirubin level that is greater than the 95th percentile ("high risk zone") based on the Bhutani nomogram(1), for the case population. * Age at enrollment less than 7 days or less than or equal to 168 hours. * No major anomalies (chromosomal abnormalities, cyanotic congenital heart disease, gastroschisis, omphalocele, diaphragmatic hernia, or other major gastrointestinal anomalies, major neurological injury or anomaly, and multiple congenital anomalies). * Ability to follow subjects transferred to another facility for outcome data. Control * Documentation of informed consent. * Gestational age greater than or equal to 37 weeks. * Birth weight greater than or equal to 2000 grams. * At least one estimate of serum bilirubin. Bilirubin level estimated to be less than the 40th percentile ("low risk zone") based on the Bhutani nomogram. While a serum bilirubin in the low risk zone is the preferred method for assessing the bilirubin level, many pediatricians use transcutaneous measure of bilirubin as a screening tool for identifying "low risk" patients. For this reason, we will allow controls to be identified using transcutaneous measurements and collect serum bilirubin levels only as clinically indicated. * Age at enrollment less than 7 days or less than or equal to 168 hours. * No major anoma…