Factors influencing bilirubin elevation and its correlation with UGT1A1 gene polymorphism in the early postoperative period of transjugular intrahepatic portosystemic shunt / 中华肝脏病杂志

Objective: To investigate the factors influencing total bilirubin elevation and its correlation with UGT1A1 gene polymorphism in the early postoperative period of transjugular intrahepatic portosystemic shunt (TIPS). Methods: 104 cases with portal hypertension and esophageal variceal hemorrhage (EVB) treated with elective TIPS treatment were selected as the study subjects and were divided into a bilirubin-elevated group and a normal bilirubin group according to the total bilirubin elevation level during the early postoperative period. Univariate analysis and logistic regression were used to analyze the factors influencing total bilirubin elevation in the early postoperative period. PCR amplification and first-generation sequencing technology were used to detect the polymorphic loci of the UGT1A1 gene promoter TATA box, enhancer c.-3279 T > G, c.211G > A, and c.686C > A. Logistic regression was used to analyze the correlation of four locus alleles and genotypes with elevated total bilirubin in the early postoperative period. Results: Among the 104 cases, 47 patients were in the bilirubin elevated group, including 35 males (74.5%) and 12 females (25.5%), aged (50.72 ± 12.56) years. There were 57 cases in the normal bilirubin group, including 42 males (73.7%) and 15 females (26.3%), aged (51.63 ± 11.10) years. There was no statistically significant difference in age (t = -0.391, P = 0.697) and gender (χ(2) = 0.008, P = 0.928) between the two groups of patients. Univariate analysis revealed that preoperative alanine transaminase (ALT) level (χ(2) = 5.954, P = 0.015), total bilirubin level (χ(2) = 16.638, P < 0.001), MELD score (χ(2) = 10.054, P = 0.018), Child-Pugh score (χ(2) = 6.844, P = 0.022), and postoperative portal vein branch development (χ(2) = 6.738, P = 0.034) were statistically significantly different between the two groups. Logistic regression analysis showed that preoperative ALT level, total bilirubin level, and portal vein branch development after TIPS were correlated with the elevated total bilirubin in the early postoperative period. The polymorphism of the c.211G > A locus of the UGT1A1 gene correlation had elevated total bilirubin in the early postoperative period of TIPS. The risk of elevated total bilirubin was increased in the population carrying allele A (P = 0.001, OR = 4.049) in the early postoperative period. Allelic polymorphisms in the TATA box promoter region and enhancer c.-3279 T > G and c.686C > A had no statistically significant difference between the bilirubin-elevated group and the normal bilirubin group. Conclusion: The preoperative ALT level, total bilirubin level, and portal vein branch development are correlated with the elevated total bilirubin in early postoperative patients. The polymorphisms of the UGT1A1 gene and enhancer c.211G > A are correlated with the occurrence of elevated total bilirubin in the early postoperative period of TIPS. Allele A carrier may have a higher risk of elevated total bilirubin in the early postoperative period.

UGT1A1 gene mutations in Chinese Dong neonates in Sanjiang, Guangxi / 中国当代儿科杂志

OBJECTIVES@#To study the characteristics of UGT1A1 gene mutations in Dong neonates in Sanjiang County of Liuzhou and its association with the pathogenesis of hyperbilirubinemia in Dong neonates.@*METHODS@#A prospective analysis was performed on 84 neonates who were diagnosed with unexplained hyperbilirubinemia in the Department of Neonatology, Sanjiang County People's Hospital, from January 2021 to January 2022. Sixty healthy neonates born during the same period were enrolled as the control group. Peripheral blood genomic DNA was extracted for both groups, and UGT1A1 exon 1 was amplified by PCR and sequenced.@*RESULTS@#In the case group, 33 neonates were found to have G71R missense mutation, with a mutation rate of 39%. The case group had a significantly higher frequency of A allele than the healthy control group (21% vs 10%, P<0.05). The risk of hyperbilirubinemia in Dong neonates carrying G71R missense mutation was 2.588 times as high as that in healthy neonates carrying wild-type UGT1A1 gene (P<0.05). Hardy-Weinberg equilibrium testing showed that the UGT1A1 G71R locus was in genetic equilibrium in both groups (P>0.05).@*CONCLUSIONS@#UGT1A1 G71R mutation is a high-frequency gene mutation type in Dong neonates in Sanjiang County, and G71R missense mutation is associated with hyperbilirubinemia in Dong neonates.

Characteristics and Clinical Implication of UGT1A1 Heterozygous Mutation in Tumor / 中国肺癌杂志

BACKGROUND@#The literature recommends that reduced dosage of CPT-11 should be applied in patients with UGT1A1 homozygous mutations, but the impact of UGT1A1 heterozygous mutations on the adverse reactions of CPT-11 is still not fully clear.@*METHODS@#A total of 107 patients with UGT1A1 heterozygous mutation or wild-type, who were treated with CPT-11 from January 2018 to September 2021 in Peking University Third Hospital, were retrospectively enrolled. The adverse reaction spectra of patients with UGT1A1*6 and UGT1A1*28 mutations were analyzed. Adverse reactions were evaluated according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) 5.0. The efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The genotypes of UGT1A1*6 and UGT1A1*28 were detected by digital fluorescence molecular hybridization.@*RESULTS@#There were 43 patients with UGT1A1*6 heterozygous mutation, 26 patients with UGT1A1*28 heterozygous mutation, 8 patients with UGT1A1*6 and UGT1A1*28 double heterozygous mutations, 61 patients with heterozygous mutation at any gene locus of UGT1A1*6 and UGT1A1*28. Logistic regression analysis showed that the presence or absence of vomiting (P=0.013) and mucositis (P=0.005) was significantly correlated with heterozygous mutation of UGT1A1*28, and the severity of vomiting (P<0.001) and neutropenia (P=0.021) were significantly correlated with heterozygous mutation of UGT1A1*6. In colorectal cancer, UGT1A1*6 was significantly correlated to diarrhea (P=0.005), and the other adverse reactions spectrum was similar to that of the whole patient cohort, and efficacy and prognosis were similar between patients with different genotypes and patients treated with reduced CPT-11 dosage or not.@*CONCLUSIONS@#In clinical use, heterozygous mutations of UGT1A1*6 and UGT1A1*28 are related to the risk and severity of vomiting, diarrhea, neutropenia and mucositis in patients with Pan-tumor and colorectal cancer post CPT-11 therpy. In colorectal cancer, UGT1A1*6 is significantly related to diarrhea post CPT-11 use, efficacy and prognosis is not affected by various genotypes or CPT-11 dosage reduction.

Comprehensive Variant Screening of the UGT Gene Family

PURPOSE: UGT1A1, UGT2B7, and UGT2B15 are well-known pharmacogenes that belong to the uridine diphosphate glucuronyltransferase gene family. For personalized drug treatment, it is important to study differences in the frequency of core markers across various ethnic groups. Accordingly, we screened single nucleotide polymorphisms (SNPs) of these three genes and analyzed differences in their frequency among five ethnic groups, as well as attempted to predict the function of novel SNPs. MATERIALS AND METHODS: We directly sequenced 288 subjects consisting of 96 Korean, 48 Japanese, 48 Han Chinese, 48 African American, and 48 European American subjects. Subsequently, we analyzed genetic variability, linkage disequilibrium (LD) structures and ethnic differences for each gene. We also conducted in silico analysis to predict the function of novel SNPs. RESULTS: A total of 87 SNPs were detected, with seven pharmacogenetic core SNPs and 31 novel SNPs. We observed that the frequencies of UGT1A1 *6 (rs4148323), UGT1A1 *60 (rs4124874), UGT1A1 *93 (rs10929302), UGT2B7 *2 (rs7439366), a part of UGT2B7 *3 (rs12233719), and UGT2B15 *2 (rs1902023) were different between Asian and other ethnic groups. Additional in silico analysis results showed that two novel promoter SNPs of UGT1A1 -690G>A and -689A>C were found to potentially change transcription factor binding sites. Moreover, 673G>A (UGT2B7), 2552T>C, and 23269C>T (both SNPs from UGT2B15) changed amino acid properties, which could cause structural deformation. CONCLUSION: Findings from the present study would be valuable for further studies on pharmacogenetic studies of personalized medicine and drug response.

A Case of Hereditary Spherocytosis Coexisting with Gilbert's Syndrome / 대한소화기학회지

We recently encountered a case of hereditary spherocytosis coexisting with Gilbert's syndrome. Patient was initially diagnosed with Gilbert's syndrome and observed, but other findings suggestive of concurrent hemolysis, such as splenomegaly and gallstones were noted during the follow-up period. Therefore, further evaluations, including a peripheral blood smear, osmotic fragility test, autohemolysis test, and red blood cell membrane protein test were performed, and coexisting hereditary spherocytosis was diagnosed. Genotyping of the conjugation enzyme uridine diphosphate-glucuronosyltransferase was used to confirm Gilbert's syndrome. Because of the high prevalence rates and similar symptoms of these 2 diseases, hereditary spherocytosis can be masked in patients with Gilbert's syndrome. In review of a case and other article, the possibility of the coexistence of these 2 diseases should be considered, especially in patients with unconjugated hyperbilirubinemia who also have splenomegaly and gallstones.

Polymorphisms of UGT1A1*6, UGT1A1*27 & UGT1A1*28 in three major ethnic groups from Malaysia.

Background & objectives: Genetic polymorphisms of uridine diphosphate glucuronyltransferase 1A1 (UGT1A1) have been associated with a wide variation of responses among patients prescribed with irinotecan. Lack of this enzyme is known to be associated with a high incidence of severe toxicity. The objective of this study was to investigate the prevalence of three different variants of UGT1A1 (UGT1A1*6, UGT1A1*27 and UGT1A1*28), which are associated with reduced enzyme activity and increased irinotecan toxicity, in the three main ethnic groups in Malaysia (Malays, Chinese and Indians). Methods: A total of 306 healthy unrelated volunteers were screened for UGT1A1*28, UGT1A1*6 and UGT1A1*27. Blood samples (5 ml) were obtained from each subject and DNA was extracted. PCR based methods were designed and validated for detection of UGT1A1*6, UGT1A1*27 and UGT1A1*28. Direct DNA sequencing was performed to validate the results of randomly selected samples. Results: Malays and Indian have two-fold higher frequency of homozygous of UGT1A1*28 (7TA/7TA) which was 8 and 8.8 per cent, respectively compared to the Chinese (4.9%). However, the distribution of UGT1A1*6 and UGT1A1*27 showed no significant differences among them. UGT1A1*27 which has not been detected in Caucasian and African American population, was found in the Malaysian Malays (3.33%) and Malaysian Chinese (2.0%). Interpretation & conclusions: There was interethnic variability in the frequency of UGT1A1*28 in the Malaysian population. Our results suggest that genotyping of UGT1A1*6, UGT1A1*28 and UGT1A1*27 need to be performed before patients are prescribed with irinotecan due to their high prevalence of allelic variant which could lead to adverse drug reaction.

Crigler-Najjar syndrome type 2: Novel UGT1A1 mutation.

Crigler-Najjar syndrome type 2 is a rare cause for persistent unconjugated hyperbilirubinemia, inherited in an autosomal recessive manner. Even though it is compatible with normal life span, in the absence of prompt suspicion and intensive management it can prove fatal not only in the neonatal period but also during adult life. Here, we describe a case with a novel homozygous UGT1A1 p.Pro176Leu mutation.

Wayward effect of polymorphism (TA)8 in the promoter region of UGT1A1 gene in a Mexican family / Efecto caprichoso del polimorfismo (TA)8 en la región del promotor del gene UGT1A1 en una familia mexicana

Gilbert syndrome (GS) is a hereditary relatively common benign unconjugated hyperbilirubinaemia. The promoter region of uridine diphosphate glycosyltransferase 1 (UGT1A1) gene contains a normal A(TA)6 TAA element; variations in this motif (A(TA)7/8 TAA) are generally associated with this disorder. This is a report of the varied effects of GS in a Mexican Mestizo family with a non-common (TA)8 repeat in this population. T he proposita and her mother showed (TA)7 /(TA)8 genotype, while her father and sister were (TA)6 /(TA)7 , but only the proposita showed clinical manifestations. This report supports that the (TA)7 and (TA)8 are necessary, but not enough to explain the features of GS. There are probably additional genetic variations ie, the presence of "modifier" genes or one can speculate that an oligogenetic trait can contribute to the expression of the final phenotype.

El síndrome de Gilberto (SG) es un hiperbilirubinemia no conjugada, benigna, relativamente común y hereditaria. La región promotora del gen (UGT1A1) de la uridina difosfato glicosiltransferasa 1, contiene un elemento normal A (TA)6 TAA. Las variaciones en este motivo (A (TA)7/8 TAA) se encuentran por lo general asociadas con este desorden. Éste es un reporte de los variados efectos del SG en una familia mestiza mexicana con una repetición (TA)8 no común en esta población. La probando y su madre mostraron el genotipo (TA)7 /(TA)7 , mientras su padre y hermana eran (TA)6 /(TA)7 , pero sólo la probando mostró manifestaciones clínicas. Este informe sostiene que el (TA)7 y (TA)8 son necesarios, pero no suficientes para explicar los rasgos del SG. Probablemente hay variaciones genéticas adicionales, es decir, la presencia de genes "modificadores", o se puede especular que un rasgo oligogenético puede contribuir a la expresión del fenotipo final.

Transcriptional Regulation of Proteoglycans and Glycosaminoglycan Chain-synthesizing Glycosyltransferases by UV Irradiation in Cultured Human Dermal Fibroblasts

Various kinds of glycosaminoglycans (GAGs) and proteoglycans (PGs) have been known to be involved in structural and space-filling functions, as well as many physiological regulations in skin. To investigate ultraviolet (UV) radiation-mediated regulation of GAGs and PGs in cultured human dermal fibroblasts, transcriptional changes of many types of PGs and GAG chain-synthesizing enzymes at 18 hr after 75 mJ/cm2 of UV irradiation were examined using quantitative real-time polymerase chain reaction methods. Hyaluronic acid synthase (HAS)-1, -2, and -3 and hyaluronidase-2 mRNA expressions were significantly increased by UV irradiation. Expressions of lumican, fibromodulin, osteoglycin, syndecan-2, perlecan, agrin, versican, decorin, and biglycan were significantly decreased by UV irradiation, while syndecan-1 was increased. Expressions of GAG chain-synthesizing glycosyltransferases, xylosyltransferase-1, beta1,3-glucuronyltransferase-1, beta1,4-galactosyltransferase-2, -4, exostosin-1, chondroitin polymerizing factor, and chondroitin sulfate synthase-3 were significantly reduced, whereas those of beta1,3-galactosyltransferase-6, beta1,4-galactosyltransferase-3, -7, beta-1,3-N-acetylglucosaminyltran sferase-2, and -7 were increased by UV irradiation. Heparanase-1 mRNA expression was increased, but that of heparanase-2 was reduced by UV irradiation. Time-course investigation of representative genes showed consistent results. In conclusion, UV irradiation may increase hyaluronic acid production through HAS induction, and decrease other GAG productions through downregulation of PG core proteins and GAG chain-synthesizing glycosyltransferases in cultured human dermal fibroblasts.

Farmacogenética y reacción adversa a medicamentos: valor predictivo delpolimorfismo en el gen de la uridindifosfato glucuronosil transferasa 1A1 / Farmacogenetics and adverse reaction to drugs: predictive value of polymorphism in the uridine diphosphate glucoronosyltransferase 1A1 gene

Introducción: las reacciones adversas a medicamentos constituyen un problema fundamental para los servicios de salud, la industria farmacéutica y los organismos reguladores. Gran parte de estas reacciones son relativamente leves y desaparecen al modificar la dosis, pero otras son más graves, pudiendo llegar a la muerte del individuo. El irinotecán es un agentecitotóxico activo en cáncer colorrectal y pulmonar. Está asociado a una severa toxicidad hematológica y gastrointestinal, impredecibles en la práctica. Su metabolito activo (SN-38)es detoxificado mediante la enzima UDP-glucuronosiltransferasa-1A1 (UGT1A1). La variación en la actividad de esta enzima ha sido relacionada con polimorfismos en el gen UGT1A1, produciendo los efectos adversos observados. El polimorfismo más importante se presenta en la región promotora y consiste en un número variable de repeticiones timinaadenina.El alelo mayoritario tiene seis repeticiones (TA)6, siendo el polimorfismo de siete repeticiones la variante alélica más frecuente.Objetivo: diseño de un ensayo molecular para el estudio de las variantes alélicas de la región promotora del gen UGT1A1.Material y método: se seleccionó un grupo de 50 voluntarios sin vínculo familiar. Las determinaciones moleculares se realizaron mediante amplificación y posterior secuenciaciónde la región promotora. Resultados y conclusiones: se logró la puesta a punto del diagnóstico molecular propuesto yse determinó que 8% de esa población es homocigoto (TA)7. Planteamos la ventaja de incorporar los resultados de este ensayo molecular en la toma de decisiones terapéuticas y así tender a una farmacoterapia personalizada en medicina oncológica.

Introduction: adverse reactions to drugs constitute an essential problem for health services, the pharmaceuticalindustry and the regulatory bodies. Most of these reactions are relatively mild and they disappear when dosageis modified, although others are more serious and they may result in death. Irinotecan is an active cytotoxic agentin colorectal and lung cancer. It is associated to severe hematological and gastrointestinal toxicity, unpredictablein practice. Its active metabolite (SN-38) is detoxified by the uridine diphosphate glucoronosyltransferase1A1enzyme (UGT1A1). (UGT1A1). Variation in the activity of this enzyme has been associated to polymorphismsin the UGT1A1 gene, what results in the adverse reactions observed. The most important polymorphisms appearin the polymorphism of the promoting region, which consists in a variable repetition of thymine-adenine repetitions. The main allele has six repetitions (TA)6, being the seven repetition polymorphism the most frequent allelic variant. Objetive: to design a molecular test to study allelicvariants of the promoting region in the UGT1A1 gene. Method: We selected a group of 50 volunteers with no family bonds. Amplification and subsequent sequencing of the promoting region were used to determine molecules.Results: we managed to update the suggested molecular diagnosis and determined that 8% of this populationis a homozygote (TA)7. We propose the advantage of incorporating the results of this molecular test for the making of therapeutic decisions and thus make progress toward a more personalized oncologic medicine.

Introdução: as reações adversas a medicamentos são um problema importante para os serviços de saúde, a indústria farmacêutica e os organismos reguladores. Muitas destas reações são relativamente leves e desaparecem com a modificação da dose, porém outras são mais graves podendo levar à morte do paciente. O irinotecan é um agentecitotóxico ativo em câncer colorretal e pulmonar. Está associado à toxicidade hematológica e gastrointestinal grave, imprevisível na prática. Seu metabólito ativo (SN-38) é detoxificado pela enzima UDP-glucuronosiltransferase-1A1 (UGT1A1). A variação da atividade desta enzima foi relacionada com polimorfismos no gene UGT1A1,produzindo os efeitos adversos observados. O polimorfismo mais importante se apresenta na região promotora e consiste num número variável de repetições timinaadenina.O alelo mais numeroso tem seis repetições (TA)6, sendo que o polimorfismo de sete repetições é a variante alélica mais frequente.Objetivo: projeto de um ensaio molecular para estudar as variantes dos alelos da região promotora do geneUGT1A1. Material e método: um grupo de 50 voluntários sem vínculo familiar foi selecionado. As determinações moleculares foram realizadas por amplificação e posterior seqüenciação da região promotora. Resultados e conclusões: foi possível realizar o diagnóstico molecular proposto e determinar que 8% da população estudada era homozigota. (TA)7. Discutimos a vantagem de incorporar os resultados deste ensaio molecularna tomada de decisões terapêuticas e dessa forma estabelecer uma tendência à farmacoterapia personalizadaem oncologia.

Una variedad genética de la UDP-glucuronosil transferasa asociada a toxicidad gastrointestinal por irinotecan / A prevalent genetic variety of UDP-glycuronosyl transferase predicts high risk of irinotecan toxicity

Los avances en genética y biología molecular han impulsado la aparición de nuevas áreas de estudio en la medicina, como la farmacogenómica, la cual intenta predecir la respuesta y toxicidad a drogas en función de la variabilidad genética de cada individuo, constituyendo los llamados síndromes fármacogenómicos. La oncología podría beneficiarse debido a la gran toxicidad de sus fármacos. Hay varios loci genéticos que se están analizando por su potencial valor predictivo y hasta ahora sólo tres de ellos demostraron cierto grado de utilidad clínica. En especial, el estudio del número de repeticiones del dinucleótido timina-adenina (TA) en el promotor de la enzima UDP-glucuronosil-transferasa (UGT) mostró ser capaz de predecir neutropenia severa en pacientes expuestos a dosis intermedias y altas de irinotecan. Comunicamos el caso de una paciente con cáncer de pulmón de células pequeñas que padeció toxicidad hematológica y gastrointestinal grave tras haber sido tratada con dosis relativamente bajas (65 mg/m2) de irinotecan, y en quien un análisis del ADN leucocitario mostró la presencia de homocigosis para siete repeticiones de TA. Este caso es un ejemplo de aplicabilidad clínica del test, se discute su utilidad como predictor de toxicidad y la conducta a tomar frente a pacientes con estas características.

The advances in genetics and molecular biology have raised new areas in medicine, such as pharmacogenomics, which tries to predict drug responses and toxicities based on the individual genetic variability, describing the so called: pharmacogenomic syndromes. Oncology would find this development extremely useful because of the severe toxicity of chemotherapy. There are a lot of genetic loci under investigation for their potential in predicting drug toxicity, but only three of them have showed clinical usefulness up to now. In particular, quantification of the number of thymine-adenine (TA) dinucleotics in the promoter region of the UDP-glucuronosyl-transferase 1A1 enzime (TA indel) proved to be capable of predicting severe neutropenia in patients exposed to intermediate or high doses of irinotecan. Herein we report a case of a patient with small cell lung cancer who suffered severe hematological and gastrointestinal toxicity after being treated with relatively low doses (65 mg/m2) of irinotecan and whose leucocyte DNA analysis showed the presence of seven TA repetitions in both alleles. This case is an example of the clinical applicability and the utility of the test as a toxicity predictor. We also discuss the clinical decisions that may be taken with these patients.

A Study of Polymorphism in UDP-glucuronosyltransferase 1 (UGT-1A1) Promoter Gene in Korean Patients with Gilbert's Syndrome / 대한간학회지

BACKGROUNDS/AIMS: Hepatic glucuronidating activity, essential for efficient biliary excretion of bilirubin, is reduced to about 30 percent of normal in patients with Gilbert's syndrome. Patients with Gilbert's syndrome have an additional TA insertion in the A(TA)TAA of UDP-glucuronosyltransferase 1 (UGT-1A1) promoter gene. This results in reduced frequency and accuracy of transcription initiation and enzyme activity. The frequency and location of the mutation vary according to races. This study was done to determine the UGT-1A1 promoter gene mutation in Korean cases of Gilbert's syndrome. METHODS: Promoter regions of the gene for bilirubin UGT-1A1 in twelve patients with Gilbert's syndrome and twenty healthy subjects (controls) were sequenced. RESULTS: 1) Among twelve Gilbert's syndrome five patients were homozygous for A(TA)6/6TAA, two were homozygous for A(TA)7/7TAA, and the other five were heterozygous for A(TA)6/7TAA. The prevalence of A(TA)TAA mutation was 58.3 percent. 2) Among twenty healthy subjects seventeen were homozygous for A(TA)6/6TAA, one was homozygous for A(TA)7/7TAA, and two were heterozygous for A(TA)6/7TAA. The prevalence of A(TA)TAA mutation was 15 percent. 3) The prevalence of A(TA)TAA mutation in Gilbert's syndrome patients was significantly higher than in the controls (p=0.018). CONCLUSION: Although the prevalence of A(TA)TAA mutation in Korean patients with Gilbert's syndrome is significantly higher than in the controls, the mutations of the promoter region of UGT-1A1 gene appear not to be the main or sole cause in Gilbert's syndrome in Korea since the prevalence of A(TA)TAA mutation is not so high. Further studies to determine the relationship between other UGT-1A1 gene mutation and Gilbert's syndrome in Korea are needed.

UDP glucuronosyltransferase 1 [UGT1A1] gene promoter polymorphism among Kuwaitis with glucose-6-phosphate dehydrogenase [G6PD] deficiency

The polymorphic [TA]7 allele of the UGT1A1 gene results in decreased bilirubin conjugation. As a genetic co-factor, it can trigger neonatal jaundice in G6PD deficient individuals. In Kuwait, the incidence of G6PD deficiency is quite high. There are no data, however, on the frequency of the [TA]7 allele and it is not known how f requently this polymorphism occurs with G6PD deficiency. To answer this question, the UGT1A1 gene p romoter polymorphism was studied among G6PD deficient Kuwaitis was analyzed using polymerase chain reaction followed by polyacrylamide gel electrophoresis. Among 55 unrelated Kuwaiti blood donors with G6PD deficiency caused by the Mediterranean mutation, nine individuals were found to be homozygous and 26 heterozygous for the [TA]7. The frequencies of the [TA]6 and [TA]7 alleles were 0.6 and 0.4, respectively. High frequency of the [TA]7 allele and Mediterranean mutation among Kuwaitis may produce neonatal jaundice in up to 1% of the male and 0.6% of the female newborns