Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena / Prevalence of Gilbert syndrome and its genetic determinants in Chile

Background: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. Aim: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. Material and Methods: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. Results: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. Conclusions: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

[Prevalence of Gilbert syndrome and its genetic determinants in Chile]. / Prevalencia de síndrome de Gilbert y sus determinantes genéticas en población chilena.

BACKGROUND: In Europeans the TATA box TA7 repeat promoter variant in the UGT1A1 gene (UGT1A1*28) is the major determinant of bilirubin levels. AIM: To study the prevalence of Gilbert Syndrome (GS) and its genetic determinants in Chile. MATERIAL AND METHODS: Three different studies were conducted. The prevalence of GS in Chile was assessed in 991 subjects with normal liver tests (ALT and GGT) from the 2nd National Health Survey. We defined GS as a total bilirubin (TB) between 1.4-5mg/dL. The second study assessed the genotype prevalence of SNP rs6742078 (in LD with UGT1A1*28) and rs4149056 in 500 DNA samples of non-related Hispanics. Finally, a case-control study was designed to assess the phenotype-genotype correlation. UGT1A1*28 and rs4149056 variants were determined by direct sequencing and allelic discrimination assays (TaqMan), respectively. RESULTS: Prevalence of GS in the general Chilean population was 2.6% (4.5% in males and 0.5% in female). No correlation with age, educational level or home location was found. Genotypes for UGT1A1*28 (TA6/6 50.5%, TA6/7 37.8%, TA7/7 11.7%) and rs4149056 (TT 74.1%, CT 22.8%, and CC 3.1%) variants were similar to Europeans. In the case-control study, most patients with GS were homozygotes for UGT1A1*28 (TA7/7, 74%). Of note, 44% of patients with intermediate TB levels were also TA7/7, compared to 7% in normal subjects. SLCO1B1 genotype was not correlated with TB levels. CONCLUSIONS: While the prevalence of GS was lower in Chile compared to Europeans (~5%), the prevalence of UGT1A1*28 homozygotes was similar (~12%). In Chilean Hispanics, the UGT1A1*28 variant explain 75% of GS phenotype.

Pruebas de laboratorio en el síndrome de Gilbert consecutivo a hepatitis / Laboratory tests in Gilbert's syndrome subsequent to hepatitis

Se efectuó un estudio descriptivo y transversal de 40 pacientes con síndrome de Gilbert consecutivo a hepatitis viral aguda, admitidos en el Servicio de Medicina Interna del Hospital Provincial Docente Clinicoquirúrgico Saturnino Lora Torres de Santiago de Cuba o en la consulta especializada de Hepatología del Policlínico de Especialidades de esta institución, desde junio del 2011 hasta igual mes del 2012, a fin de determinar las características clínico humorales y la respuesta al tratamiento médico en estos. En la casuística se evaluaron las medias, medianas y desviaciones estándares, y entre los resultados se observaron una mayor representación de los hombres menores de 36 años (90,0 por ciento del total), así como un predominio de las manifestaciones de somnolencia, seguida de la astenia, ictericia leve y ausencia de síntomas; asimismo, se confirmó la elevación de la bilirrubina indirecta y su posterior disminución al aplicar la terapia con un inductor enzimático, en este caso el fenobarbital, con el cual se obtuvo, finalmente, mejoría clínica y humoral de los afectados

A descriptive and cross-sectional study was carried out in 40 patients with Gilbert's syndrome subsequent to viral hepatitis, admitted to the Internal Medicine Department of Saturnino Lora Torres Provincial Clinical Surgical Teaching Hospital of Santiago de Cuba or to the specialized hepatology service of the Polyclinic of Specialties in this institution, from June 2011 to the same month of 2012, to determine the clinical and humoral characteristics and the response to medical treatment in them. Means, medians and standard deviations were evaluated in the case material, and among the results was a greater representation of males younger than 36 years (90.0 percent of the total), and a prevalence of manifestations of drowsiness, followed by sleepiness, mild jaundice and absence of symptoms was observed. Also, the elevation of indirect bilirrubin and its subsequent reduction when applying therapy with an enzyme inducer, phenobarbital in this case, were confirmed, eventually obtaining clinical and humoral improvement of patients

Pruebas de laboratorio en el síndrome de Gilbert consecutivo a hepatitis / Laboratory tests in Gilbert's syndrome subsequent to hepatitis

Se efectuó un estudio descriptivo y transversal de 40 pacientes con síndrome de Gilbert consecutivo a hepatitis viral aguda, admitidos en el Servicio de Medicina Interna del Hospital Provincial Docente Clinicoquirúrgico Saturnino Lora Torres de Santiago de Cuba o en la consulta especializada de Hepatología del Policlínico de Especialidades de esta institución, desde junio del 2011 hasta igual mes del 2012, a fin de determinar las características clínico humorales y la respuesta al tratamiento médico en estos. En la casuística se evaluaron las medias, medianas y desviaciones estándares, y entre los resultados se observaron una mayor representación de los hombres menores de 36 años (90,0 por ciento del total), así como un predominio de las manifestaciones de somnolencia, seguida de la astenia, ictericia leve y ausencia de síntomas; asimismo, se confirmó la elevación de la bilirrubina indirecta y su posterior disminución al aplicar la terapia con un inductor enzimático, en este caso el fenobarbital, con el cual se obtuvo, finalmente, mejoría clínica y humoral de los afectados(AU)

A descriptive and cross-sectional study was carried out in 40 patients with Gilbert's syndrome subsequent to viral hepatitis, admitted to the Internal Medicine Department of Saturnino Lora Torres Provincial Clinical Surgical Teaching Hospital of Santiago de Cuba or to the specialized hepatology service of the Polyclinic of Specialties in this institution, from June 2011 to the same month of 2012, to determine the clinical and humoral characteristics and the response to medical treatment in them. Means, medians and standard deviations were evaluated in the case material, and among the results was a greater representation of males younger than 36 years (90.0 percent of the total), and a prevalence of manifestations of drowsiness, followed by sleepiness, mild jaundice and absence of symptoms was observed. Also, the elevation of indirect bilirrubin and its subsequent reduction when applying therapy with an enzyme inducer, phenobarbital in this case, were confirmed, eventually obtaining clinical and humoral improvement of patients(AU)

Loci from a genome-wide analysis of bilirubin levels are associated with gallstone risk and composition.

BACKGROUND & AIMS: Genome-wide association studies have mapped loci that are associated with serum levels of bilirubin. Bilirubin is a major component of gallstones so we investigated whether these variants predict gallstone bilirubin content and overall risk for gallstones. METHODS: Loci that were identified in a meta-analysis to attain a genome-wide significance level of a P value less than 1.0×10(-7) (UGT1A1, SLCO1B1, LST-3TM12, SLCO1A2) were analyzed in 1018 individuals with known gallstone composition. Gallstone risk was analyzed in 2606 German choleystecomized individuals and 1121 controls and was replicated in 210 cases and 496 controls from South America. RESULTS: By using the presence of bilirubin as a phenotype, variants rs6742078 (UGT1A1; P = .003), rs4149056 (SLCO1B1; P = .003), and rs4149000 (SLCO1A2; P = .015) were associated with gallstone composition. In regression analyses, only UGT1A1 and SLCO1B1 were independently retained in the model. UGT1A1 (rs6742078; P = .018) was associated with overall gallstone risk. In a sex-stratified analysis, only male carriers of rs6742078 had an increased risk for gallstone disease (P = 2.1×10(-7); odds ratio(recessive), 2.34; P(women) = .47). The sex-specific association of rs6742078 was confirmed in samples from South America (P(men) = .046; odds ratio(recessive), 2.19; P(women) = .96). CONCLUSIONS: The UGT1A1 Gilbert syndrome variant rs6742078 is associated with gallstone disease in men; further studies are required regarding the sex-specific physiology of bilirubin and bile acid metabolism. Variants of ABCG8 and UGT1A1 are the 2 major risk factors for overall gallstone disease, they contribute a population attributable risk of 21.2% among men.