Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Elevated erythrocyte destruction in sickle cell disease (SCD) results in chronic hyperbilirubinaemia and, in a subset of patients, cholelithiasis occurs. We investigated whether the (TA)n promoter polymorphism in the UDP-glucuronosyltransferase 1A1 gene (UGT1A1) may modify bilirubin metabolism, influencing bilirubinaemia, predisposition to cholelithiasis and subsequent cholecystectomy, in a group of 153 young SCD patients (mean age 12.0 +/- 9.0 years) predominantly of Bantu beta S haplotype. The concomitant effect of alpha thalassaemia was also analysed. Among the several UGT1A1 genotypes found, the most frequent were the (TA)6/(TA)6 (n = 37), (TA)6/(TA)7 (n = 60) and (TA)7/(TA)7 (n = 29). These groups of patients did not significantly differ in age, gender ratio and haemoglobin, foetal haemoglobin and reticulocyte levels. On the other hand, total bilirubin levels were significantly different between groups, with an increased (TA) repeat number being associated with higher bilirubinaemia. Furthermore, both cholelithiasis and cholecystectomy were more frequent in groups with higher (TA) repeat number, although the former association was not statistically significant. None of the mentioned parameters is statistically different within UGT1A1 groups with the presence of alpha thalassaemia. Thus, the UGT1A1 promoter polymorphism may represent an important nonglobin genetic modifier of Bantu SCD patients' clinical manifestations, even at a young age.
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PMID:Early modification of sickle cell disease clinical course by UDP-glucuronosyltransferase 1A1 gene promoter polymorphism. 1839 54

Genetic modifiers contribute to phenotypic variability in patients with sickle cell anemia (SCA). The influence of the bilirubin UDP-glucuronosyltransferase (UGT) 1A1 (TA)(n)TAA promoter polymorphism on bilirubin levels and gallbladder disease in SCA was examined using prospectively collected data from the Cooperative Study of Sickle Cell Disease. A total of 324 children with HbSS (median age 6.9 years) had UGT1A1 genotyping; 243 (75%) had common (TA)(6) or (TA)(7) alleles, whereas 81 (25.0%) had variant (TA)(5) or (TA)(8) alleles. The UGT1A1 genotype significantly influenced average bilirubin levels for the common alleles: 6/6 genotype = 2.36 +/- 1.13 mg/dL, 6/7 genotype = 2.90 +/- 1.54 mg/dL, and 7/7 genotype = 4.24 +/- 2.11 mg/dL (P < 0.0001). Thirty-nine percent of children with the 7/7 genotype had documented gallbladder disease, compared with 18.2% with the 6/7 genotype and only 9.9% with the wildtype 6/6 UGT1A1 genotype (P = 0.001). To analyze the (TA)(5) and (TA)(8) variant alleles, three groups were generated, showing increasing bilirubin levels with increasing TA repeats and age. Group 3 (genotypes 6/8, 7/7, and 7/8) had a significantly greater rate of bilirubin change than Groups 1 (genotypes 5/6, 5/7, and 6/6) or 2 (genotype 6/7). These results validate previous smaller studies and confirm that the UGT1A1 promoter polymorphism exerts a powerful influence on bilirubin levels and the development of gallbladder disease in children with SCA. UGT1A1 genotyping should be considered as a screening tool for predicting children most likely to develop gallbladder disease at a young age.
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PMID:UGT1A1 promoter polymorphisms and the development of hyperbilirubinemia and gallbladder disease in children with sickle cell anemia. 1875 40