Prevalence of UGT1A1 (TA)n promoter polymorphism in Panamanians neonates with G6PD deficiency

Abstract

A relationship between the polymorphism in promoter region of the UGT1A1 gene and the development of jaundice has been demonstrated recently. This polymorphism leads to 30% of normal rate transcription initiation of UGT1A1 gene, thus decreasing the bilirubin glucuronidation. The combination of the G6PD deficiency and polymorphism in neonates and adults may causepronounced hyperbilirubinaemias. The aim of this study was to analyse the variations in the UGT1A1 gene promoter in Panamanians neonates with G6PD deficiency and its association with neonatal jaundice (NJ). We identified five different genotypes of TA repeats, in 17 neonates (42.5%) the normal variant TA₆/TA₆ and in the other 57.5% of the subjects: TA₇/TA₇ (12.5%), TA₆/TA₇ (40%), TA₆/TA₈ (2.5%) and TA₆/TA₅ (2.5%). Additionally 75% of the 16 newborns that showed NJ had an abnormal variant in the promotersequence, although, there was no significant difference (P = 0.068). The risk of jaundice in neonates with TA₇ variant was thrice higher in subjects than with other alleles (P = 0.093, CI: 0.81-11.67). The TA₇ allele frequency in this study (0.325) was consistent with the global frequency and similar to Caucasians. The results proved that there is no significant relationship between promoter polymorphism in UGT1A1 and NJ in G6PD deficient Panamanian newborns. Further studies with a greater number of subjects would determine the exact relationship between marked NJ and UGT1A promoter variations.