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

The purpose of this study is to compare the demographic, metabolic, and genomic characteristics of patients who develop severe hyperbilirubinemia (serum bilirubin level in the "high risk zone of greater than the 95th percentile based on the Bhutani nomogram) to patients who never developed significant hyperbilirubinemia (bilirubin level in "low risk zone of less than the 40th percentile" on Bhutani nomogram and who did not require any treatment for hyperbilirubinemia). Our primary goal is to determine if common gene mutations occur at a greater frequency in patients with severe hyperbilirubinemia than in neonates without significant hyperbilirubinemia.

The gene mutations we will test for are:

• Glucose-6-phosphate Dehydrogenase Deficiency [G6PD] gene mutations
• African A- mutation (G202A;A376G)
• The common Mediterranean mutation (C563T)
• Two common Chinese mutations (G1376T and G1388A)
• UGT1A1 polymorphism. The UGT1A1 gene polymorphisms refer to those genetic defects found to be associated with Gilbert's Syndrome, including a promoter defect (T-3263G) that disrupts a transcription regulatory site, the TA repeats promoter polymorphism, and four mutations within the coding region (G211A, C686A, C1091T, and T1456G).
• Gene polymorphism for the organic anion transporting protein (OATP-2)