Gilbert's syndrome and jaundice in glucose-6-phosphate dehydrogenase deficient neonates

Background and Objective. The pathogenesis of the hyperbilirubinemia present in approximately 30% of neonates affected by glucose-6-phosphate dehydrogenase deficiency is an unsolved problem. We evaluated the effect of Gilbert's syndrome, the most common defect of bilirubin conjugation, on the hyperbilirubinemia of these neonates. Design and Methods. One hundred and two neonates affected by glucose-6-phosphate dehydrogenase deficiency were enrolled in this study: 56 had hyperbilirubinemia and 46 had normal bilirubin levels. The analysis of the A(TA)(n)TAA motif in the promoter region of the UGT1A gene was performed by means of PCR, followed by separation on 6% denaturing polyacrylamide gel. Results. The frequency of the three different genotypes of the A(TA)(n)TAA motif was similar in the study and control groups. Our results demonstrated no difference in the percentage of homozygotes for the UGT1A (TA)7 variant associated with Gilbert's syndrome. Interpretation and Conclusions. These findings indicate that Gilbert's syndrome does not account for the hyperbilirubinemia occurring in some neonates with glucose-6-phosphate dehydrogenase deficiency. Furthermore our results suggest that hemolysis is not the major event in the pathogenesis of hyperbilirubinemia in these patients.