The inverse starving test is not a suitable provocation test for Gilbert's syndrome

Three-dimensional polyacrylamide gel-based DNA microarray method effectively identifies UDP-glucuronosyltransferase 1A1 gene polymorphisms for the correct diagnosis of Gilbert's syndrome

Gilbert's syndrome is a mild genetic liver disorder characterized by unconjugated hyperbilirubinemia due to defects in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene. The T-3279G mutation in the phenobarbital responsive enhancer module (PBREM), the TA-insertion in the TATA box, creating the A(TA)7TAA motif instead of A(TA)6TAA and the G211A mutation in coding exon 1, particularly in Asian populations, of the human UGT1A1 gene are the three common genotypes found in patients with Gilbert's syndrome. Different approaches for detecting the T-3279G, A(TA)6/7TAA and G211A mutations of the UGT1A1 gene have been described. In this study, to the best of our knowledge, we established a three-dimensional polyacrylamide gel-based DNA microarray method for the first time, in order to study UGT1A1 gene polymorphisms. This method, based on a step-by-step three-dimensional polyacrylamide gel-based DNA microarray protocol, successfully identified all possible genotypes of T-3279G, A(TA)6/7TAA and G211A in 20 patients with hyperbilirubinemia. In addition, sequencing was performed to confirm these results. The data from the current study demonstrate that the three-dimensional polyacrylamide gel microarray method has the potential to be applied as a useful, reliable and cost-effective tool to detect the T-3279G, the A(TA)6/7TAA and the G211A mutations of the UGT1A1 gene in patients with hyperbilirubinemia and thereby aid in the diagnosis of Gilbert's syndrome.

Gilbert's syndrome and the risk of death: a population-based cohort study

BACKGROUND AND AIMS

Gilbert's syndrome is a common familial hyperbilirubinemia that may reduce the risk of various age-related diseases because of the antioxidant properties of bilirubin. We conducted a large cohort study using The Health Improvement Network primary care database and compared all-cause mortality rates in those with and without Gilbert's syndrome.

METHODS

Mortality rates in patients with a diagnosis of Gilbert's syndrome and raised bilirubin level (n = 4266) were compared with those of patients with similar characteristics but with normal bilirubin levels (n = 21 968). Multivariate Poisson regression was also used to estimate adjusted mortality rate ratios.

RESULTS

During the 350 000 PYs of follow up across the Gilbert's and comparison cohorts, there were 1174 deaths. Mortality rates were 24/10 000 PYs in the Gilbert's cohort versus 50/10 000 PYs in the comparison cohort. Mortality rates were around half in patients with Gilbert's syndrome after accounting for sociodemographics and general health indicators (adjusted mortality rate ratio: 0.5 [95% confidence interval; 0.4-0.7; P < 0.001]).

CONCLUSIONS

Mortality rates observed for people with Gilbert's syndrome in the general population are almost half those of people without evidence of Gilbert's syndrome.

Bilirubin dependence on UGT1A1 polymorphisms, hemoglobin, fasting time and body mass index

In humans, bilirubin levels are influenced by different factors. This study evaluates how several nongenetic causes and the genetic UGT1A1 polymorphisms contribute for bilirubin levels, in a cohort of 146 young Caucasian females. Hematological data, bilirubin, screening of TA duplication in the UGT1A1 gene, body mass index (BMI) and body fat were determined. A questionnaire about fasting time, smoking habits, oral contraceptive therapy, caloric intake and physical activity was done. Participants were divided according to the tertiles of bilirubin. Subjects from the second and third tertile had significant rises in hemoglobin (Hb), hematocrit, mean cell Hb and mean cell Hb concentration, and a significant increased frequency for the c.-41_-40dupTA allele in homozygosity, when compared to the first tertile. Red blood cell count was significantly increased in the third tertile. Results showed that the c.-41_-40dupTA allele (genetic), Hb, BMI and fasting time (nongenetic) were the main factors associated bilirubin levels.