[UGT1A1 gene mutations in Chinese Dong neonates in Sanjiang, Guangxi]. / 广西三江县侗族新生儿UGT1A1åŸºå› å˜å¼‚åˆ†æž.

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.

Epigenetics and microRNAs in UGT1As.

UDP-glucuronosyltransferases (UGTs) are the main phase II drug-metabolizing enzymes mediating the most extensive glucuronidation-binding reaction in the human body. The UGT1A family is involved in more than half of glucuronidation reactions. However, significant differences exist in the distribution of UGT1As in vivo and the expression of UGT1As among individuals, and these differences are related to the occurrence of disease and differences in metabolism. In addition to genetic polymorphisms, there is now interest in the contribution of epigenetics and noncoding RNAs (especially miRNAs) to this differential change. Epigenetics regulates UGT1As pretranscriptionally through DNA methylation and histone modification, and miRNAs are considered the key mechanism of posttranscriptional regulation of UGT1As. Both epigenetic inheritance and miRNAs are involved in the differences in sex expression and in vivo distribution of UGT1As. Moreover, epigenetic changes early in life have been shown to affect gene expression throughout life. Here, we review and summarize the current regulatory role of epigenetics in the UGT1A family and discuss the relationship among epigenetics and UGT1A-related diseases and treatment, with references for future research.

The relationship between hyperbilirubinemia and the promoter region and first exon of UGT1A1 gene polymorphisms in Vietnamese newborns.

BACKGROUND: To investigate the relationship between unexplained indirect hyperbilirubinemia of Vietnamese newborns and the polymorphism of the promoter TATA box and exon 1 of bilirubin uridine diphosphate glucuronosyltransferase (UGT1A1) gene. METHODS: A total of 149 neonates were divided into the hyperbilirubinemia group (n = 99) and control group (n = 50). The gene polymorphisms of UGT1A1 gene in the two groups were detected by PCR and direct sequencing, which revealed the relationship between UGT1A1 polymorphism with neonatal hyperbilirubinemia of neonates. The types of UGT1A1 polymorphism in the hyperbilirubinemia group and the peak total serum bilirubin (PSB) levels with different genotypes were observed. RESULTS: (1) (TA)7 insertion mutation, 211G>A, 189C>T, 190G>A, 378C>T and 686C>A were detected. (2) The allele frequency of 211G>A allele mutation was significantly different between the two groups (p < 0.05). (3) Logistic regression analysis showed that homozygosity and heterozygosity of 211G>A were both significantly associated with neonatal hyperbilirubinemia. (4) In the hyperbilirubinemia group, the peak total serum bilirubin level of 211G>A homozygous neonates was higher than that of the wild-type neonates (p < 0.05). CONCLUSIONS: We noted that there was an association between neonates with unexplained indirect hyperbilirubinemia in Vietnam and the polymorphism of UGT1A1c.211G>A. In addition, the homozygous 211G>A polymorphism was related to the degree of hyperbilirubinemia. IMPACT: Our article provided data on UGT1A1 polymorphism distribution in the Vietnamese population, which have not been reported yet. Our findings revealed that mutations in UGT1A1 gene are risk factors for unexplained hyperbilirubinemia in Vietnamese neonates. Our article will strengthen the cognition of neonatal jaundice at the genetic level in the pediatric field in Vietnam.

Analysis of In-hospital Neonatal Death in the Tertiary Neonatal Intensive Care Unit in China: A Multicenter Retrospective Study.

BACKGROUND: Globally, the proportion of child deaths that occur in the neonatal period remains a high level of 37-41%. Differences of cause in neonate death exist in different regions as well as in different economic development countries. The specific aim of this study was to investigate the causes, characteristics, and differences of death in neonates during hospitalization in the tertiary Neonatal Intensive Care Unit (NICU) of China. METHODS: All the dead neonates admitted to 26 NICUs were included between January l, 2011, and December 31, 2011. All the data were collected retrospectively from clinical records by a designed questionnaire. Data collected from each NICU were delivered to the leading institution where the results were analyzed. RESULTS: A total of 744 newborns died during the 1-year survey, accounting for 1.2% of all the neonates admitted to 26 NICUs and 37.6% of all the deaths in children under 5 years of age in these hospitals. Preterm neonate death accounted for 59.3% of all the death. The leading causes of death in preterm and term infants were pulmonary disease and infection, respectively. In early neonate period, pulmonary diseases (56.5%) occupied the largest proportion of preterm deaths while infection (27%) and neurologic diseases (22%) were the two main causes of term deaths. In late neonate period, infection was the leading cause of both preterm and term neonate deaths. About two-thirds of neonate death occurred after medical care withdrawal. Of the cases who might survive if receiving continuing treatment, parents' concern about the long-term outcomes was the main reason of medical care withdrawal. CONCLUSIONS: Neonate death still accounts for a high proportion of all the deaths in children under 5 years of age. Our study showed the majority of neonate death occurred in preterm infants. Cause of death varied with the age of death and gestational age. Accurate and prompt evaluation of the long-term outcomes should be carried out to guide the critical decision.

UGT1A1 gene mutations and neonatal hyperbilirubinemia in Guangxi Heiyi Zhuang and Han populations.

BACKGROUND: Uridine diphosphoglucuronate-glucuronosyltransferase 1A1 (UGT1A1) gene mutation was shown to be responsible for neonatal hyperbilirubinemia. This study aimed to investigate whether UGT1A1 gene mutation is associated with neonatal hyperbilirubinemia in Guangxi Heiyi Zhuang and Han populations. METHODS: Two hundred and eighteen infants with hyperbilirubinemia (118 Heiyi Zhuang, 100 Han) and 190 control subjects (110 Heiyi Zhuang, 80 Han) were enrolled. Polymerase chain reaction and gene sequencing were used to detect the TATA-box and exon 1 of UGT1A1. RESULTS: (TA)7 insertion mutation, 211G>A (G71R), 686C>A (P229Q), and 189C>T (D63D) were detected. Logistic regression analysis showed odds ratios (OR) of 2.64 (95% confidence interval (CI) 1.64-4.24; P < 0.001) and 0.69 (95%CI 0.43-1.10; P = 0.115) for neonates who carried UGT1A1 G71R and (TA)7 insertion mutation, respectively. G71R homozygosity increased the odds of dangerous bilirubin levels by a factor 34.23, and G71R heterozygosity only by 2.10. CONCLUSION: We found that UGT1A1 G71R mutation is a risk factor for neonatal hyperbilirubinemia in Guangxi Heiyi Zhuang and Han populations. Meanwhile, the UGT1A1 (TA)7 insertion mutation is not associated with neonatal hyperbilirubinemia in the two ethnic groups.

[Research progress on the relationship between SLCO1B1 gene and neonatal jaundice].

Organic anion transporter 2 (OATP2) is an uptake transporter located on the basolateral membrane of human hepatocytes. It mediates the transportation of various organic solutes including bilirubin and impacts bilirubin metabolism. It is encoded by the gene of solute carrier organic anion transporter family member 1B1 and the gene variants that inhibit hepatic bilirubin uptake function may reduce the normal functional level of bilirubin elimination and result in neonatal hyperbilirubinemia. In recent years, some studies have indicated that variants of SLCO1B1 are associated with neonatal jaundice. This article reviews the research advance in SLCO1B1 with respect to the structure and function and the relationship between SLCO1B1 mutations and neonatal jaundice.

[Mutations in UGT1A1 gene in neonates with hyperbilirubinemia of Guangxi Heiyi Zhuang nationality].

OBJECTIVE: To study the distribution of mutations of UDP-glucuronosyltransferase 1A1 (UGT1A1) gene and its relationship with hyperbilirubinemia among neonates with hyperbilirubinemia of Guangxi Heiyi Zhuang nationality. METHODS: Total genomic DNA was extracted from the blood of 100 neonates with hyperbilirubinemia (case group) and 100 neonates without hyperbilirubinemia (control group), all of whom were selected from Guangxi Heiyi Zhuang population. TATA box and all exons of UGT1A1 gene were amplified by PCR and directly sequenced. RESULTS: (TA)7 insertion mutation in TATA box, G71R missense mutation in exon 1, and 4 single nucleotide polymorphisms (SNPs) (rs199539868, rs114982090, rs1042640 and rs8330) in exon 5 were observed. The allele frequency of G71R mutation in the case group was significantly higher than that in the control group (P<0.01). There were no significant differences in the genotype distribution and allele frequency of TATA box mutation and SNPs (rs1042640 and rs8330) between the two groups (P>0.05). The logistic regression analysis showed that the odds ratios (95% confidence intervals) of UGT1A1 TATA box mutation, G71R mutation, and SNPs (rs1042640 and rs8330) associated with the development of neonatal hyperbilirubinemia were 0.846 (0.440, 1.629), 3.932 (1.745, 8.858), 0.899 (0.364, 2.222), respectively. CONCLUSIONS: (TA)7 insertion mutation and G71R missense mutation of UGT1A1 gene are common mutation types in neonates with hyperbilirubinemia of Guangxi Heiyi Zhuang nationality. Four SNPs (rs199539868, rs114982090, rs1042640, and rs8330) was first reported in China. UGT1A1 G71R missense mutation is a risk factor for hyperbilirubinemia in neonates of Guangxi Heiyi Zhuang nationality.

[Roles of UGT 1A1 gene mutation in the development of neonatal hyperbilirubinemia in Guangxi].

OBJECTIVE: Neonatal unconjugated hyperbilirubinemia is one of the most common conditions encountered by the practicing pediatricians. Although it is usually self-limited and benign, the condition is of importance because of the rare instances in which severe hyperbilirubinemia can lead to bilirubin encephalopathy or kernicterus. The uridine diphosphate-glucuronosyl transferase 1A1 (UGT 1A1) gene controls bilirubin conjugation by determining the structure of the enzyme glucuronosyltransferase, which is synthesized in the hepatocyte. In the recent years much has been learned about the relationship between UGT 1A1 gene mutation and neonatal hyperbilirubinemia. This study aimed to investigate the roles of UGT 1A1 gene mutation in the development of neonatal hyperbilirubinemia in Guangxi. METHODS: A total of 73 cases with hyperbilirubinemia and 31 healthy neonates were enrolled. UGT 1A1 G71R genotypes were identified by the (amplification refractory mutation system, ARMS) and direct sequencing method in all the neonates. To analyze the incidence of bilirubin encephalopathy, the peak (total serum bilirubin, TSB) concentration after 72 hours of age, and the possibility of TSB > 20 mg/dl of each group. RESULTS: (1) The frequencies of allele G71R were 0.1915 in this study, 0.2329 in hyperbilirubinemia group vs. 0.097 in healthy groups. The allele gene frequency of G71R in neonatal hyperbilirubinemia was higher than that in the normal group (P < 0.05). (2) Homozygous neonates had higher possibility to develop bilirubin encephalopathy and higher TSB concentration 72 hours after birth (28.57%, 23.12 ± 4.58) than the normal group (0%, 17.68 ± 2.69). The difference between the former two was significant (P < 0.001). (3) The TSB of the 5 neonates was > 20 mg/dl in G71R homozygous type, the odds ratio and 95%CI were 7.955 (1.349, 46.899). CONCLUSION: (1) G71R mutation gene was associated with neonatal jaundice in Guangxi region. (2) The possibility of TSB > 20 mg/dl in G71R homozygous was higher than those of the wild-type. (3) The incidence of bilirubin encephalopathy and TSB concentration after 72 hours of age for neonates who were homozygous to G71R gene were higher than the wild-type.

[Relationship between glucose-6-phosphate dehydrogenase gene mutations and neonatal jaundice in Naning, Guangxi].

OBJECTIVE: To study the correlation between glucose-6-phosphate dehydrogenase (G-6-PD) activities and three common mutations of G-6-PD gene G1388A, G1376T and A95G and investigate the effects of G-6-PD gene mutations on neonatal jaundice in Nanning, Guangxi. METHODS: One hundred and twenty-four neonates from Nanning, Guangxi, with hyperbilirubinemia were enrolled. The ARMS-PCR and PCR/REA methods were used to determine G-6-PD gene mutations. G-6-PD activities were measured using the NBT method. The incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth were compared between the neonates with different genotypes and between the G-6-PD mutation and normal groups. The risk of blood serum bilirubin >340 mumol/L was evaluated by logistic regression analysis. RESULTS: Of the 124 cases, gene mutations were found in 37 cases, including G1388A (n=20), G1376T (n=14), A95G (n=4) and G1388A+A95G (n=1). Five cases (25%) showed normal G-6-PD activities in the G1388A gene mutation group and 4 (29%) had normal G-6-PD activities in the G1376T G1388A gene mutation group. All of 4 cases of A95G G1388A gene mutation showed a deficiency of G-6-PD activities. There were no significant differences in the incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth between the G1388A and G1376T G1388A gene mutation groups. The incidence of acute bilirubin encephalopathy, the peak bilirubin concentration 72 hrs after birth and the risk of serum bilirubin >340 micromol/L in the G-6-PD mutation group were not different from the normal group. CONCLUSIONS: G1388A, G1376T and A95G are common G-6-PD gene mutations in Nanning, Guangxi. The false negative results may be received when the NBT method is used for diagnosis of G-6-PD deficiency. There are similar effects on the incidence of acute bilirubin encephalopathy and the peak bilirubin concentration 72 hrs after birth between different gene mutation groups. G-6-PD gene mutations alone may not contribute to the development of acute bilirubin encephalopathy and the changes of peak bilirubin concentration 72 hrs after birth and the risk of serum bilirubin >340 micromol/L.