Slow Acetylator Genotype Research Articles

N-Acetyltransferase 2 gene polymorphism and its serum levels in vitiligo patients

ABSTRACT Background Although numerous mechanisms are involved in vitiligo pathogenesis, few studies correlate N-acetyltransferase 2 to this disease. Aim To assess the N-acetyltransferase 2 (rs1799929) gene and its serum levels in vitiligo patients. Subjects and methods In this case-control study, 65 vitiligo cases were compared to 65 age- and sex-matched healthy controls. Serum NAT2 levels and the NAT2 gene polymorphism (rs1799929) were evaluated using ELISA and real-time PCR, respectively. Results Serum N-acetyltransferase 2 levels were significantly lower in cases than in controls, 1.24 ± 0.31 vs. 2.01 ± 0.46 (p = 0.001). CC genotype was more dominant in controls (58.5%) than in cases (20%). TT and CT genotypes were more dominant in cases (30.8% and 49.2%) than in controls (13.8% and 27.7%), respectively (p = 0.001). The C allele was more prominent in controls (72.3%) than in cases (44.6%) while the T allele was more dominant in cases (55.4%) than in controls (27.7%) (p = 0.001). N-acetyltransferase 2 slow acetylator phenotype (TT genotype) was higher in cases (30.8%) than in controls (13.8%) and rapid acetylator phenotypes (CC and CT genotypes) were higher in controls (86.2%) than in cases (69.2%) (p = 0.035). Conclusion Slow acetylator genotype (TT) of NAT2 gene (rs1799929) and low serum levels of NAT2 enzyme might play a role in the susceptibility and pathogenesis of vitiligo.

Incidence and risk factors of antituberculosis drug-induced liver injury in India: A systematic review and meta-analysis.

Antituberculosis drug-induced liver injury (ATDILI) is a significant problem of tuberculosis treatment. This systematic review and meta‑analysis aimed at evaluating the incidence and risk factors of ATDILI in adult patients with tuberculosis in India. Five electronic databases were searched comprehensively for studies on Indian adult patients with tuberculosis investigating the incidence and/or risk factors of ATDILI. The relevant data was pooled in a random or fixed-effect model to calculate the pooled incidence with a 95% confidence interval (CI), standardized mean difference (MD) or odds ratio (OR). Following the screening of 3221 records, 43 studies with 12,041 tuberculosis patients were finally included. Based on the random effect model, the pooled incidence of ATDILI was 12.6% (95% CI, 9.9-15.3%, p < 0.001, I2 = 95.1%). The pooled incidence was higher in patients with daily treatment regimen compared to the thrice weekly regimen (16.5% vs. 3.5%). The concurrent hepatitis B or C infection, alcohol consumption and underlying chronic liver disease were associated with high incidence of ATDILI. The pooled incidence of acute liver failure (ALF) among ATDILI patients was 6.78% (95% CI 3.9-9.5%). Female gender (OR 1.24), older age (MD 0.26), lean body mass index (OR 3.8), hypoalbuminemia (OR 3.09), N-acetyltransferase slow acetylator genotypes (OR 2.3) and glutathione S-transferases M null mutation (OR 1.6) were found to be associated with an increased risk of ATDILI. The pooled mortality rate of ATDILI patients was 1.72% (95% CI 0.4-3.0%) overall and 71.8% (95% CI 49.3-94.2%) in case of ALF. Overall, 12.6% patients of tuberculosis in India developed ATDILI when combination of first-line antituberculosis drugs was used. An average of 7% of ATDILI patients progressed to ALF which had a high mortality rate. Older age, female, poor nutritional status and some genetic polymorphisms were identified as significant risk factors.

N-acetyltransferase 2 genetic polymorphisms and anti-tuberculosis-drug-induced liver injury: a correlation study.

Background: Considering the genetic characteristics of people with anti-tuberculosis (TB)-drug-induced liver injury (ATDILI), genetic factors and their consequences for treatment need to be studied. Objective: The correlation between N-acetyltransferase 2 (NAT2) genetic polymorphisms and ATDILI was analysed. Methods: In this study, the liver and coagulation functions of 120 patients with TB were monitored dynamically for at least 3months. The genetic polymorphisms of patients were detected by pyrosequencing, and the acetylation types of liver damage and the distribution of NAT2 genetic polymorphisms were compared and analysed. Results: The results showed that there were significant differences in the distribution of alleles and acetylation types among different groups (p < 0.05). In patients with grade 4 liver injury (liver failure), any two alleles were included, i.e., *6 and *7. Specifically, patients with fast acetylation genotypes accounted for 42.4% (14/33), those with intermediate acetylated genotypes accounted for 55.2% (32/58), and patients with slow acetylation genotypes accounted for 65.5% (19/29). Conclusion: Patients with slow acetylation genotypes had higher rates of liver failure and liver injury than those with intermediate and fast acetylation genotypes, and patients with slow acetylation genotypes containing any two alleles (*6 and *7) had a higher rate of liver failure than those with other alleles. In summary, the time of liver injury in patients with slow acetylation genotypes was earlier than the total average time, and the time of liver function recovery in patients with fast acetylation genotypes was shorter than the total average time.

Pharmacogenetic interactions of efavirenz or rifampin and isoniazid with levonorgestrel emergency contraception during treatment of HIV or tuberculosis.

In AIDS Clinical Trials Group study A5375, a pharmacokinetic trial of levonorgestrel emergency contraception, double-dose levonorgestrel (3 mg, versus standard dose 1.5 mg) offset the induction effects of efavirenz or rifampin on plasma levonorgestrel exposure over 8 h post-dose (AUC 0-8h ). We characterized the pharmacogenetics of these interactions. Cisgender women receiving efavirenz- or dolutegravir-based HIV therapy, or on isoniazid-rifampin for tuberculosis, were followed after a single oral dose of levonorgestrel. Linear regression models, adjusted for BMI and age, characterized associations of CYP2B6 and NAT2 genotypes (which affect plasma efavirenz and isoniazid exposure, respectively) with levonorgestrel pharmacokinetic parameters. Of 118 evaluable participants, 17 received efavirenz/levonorgestrel 1.5 mg, 35 efavirenz/levonorgestrel 3 mg, 34 isoniazid-rifampin/levonorgestrel 3 mg, and 32 (control group) dolutegravir/levonorgestrel 1.5 mg. There were 73 Black and 33 Asian participants. Regardless of genotype, women on efavirenz and isoniazid-rifampin had higher levonorgestrel clearance. In the efavirenz/levonorgestrel 3 mg group, CYP2B6 normal/intermediate metabolizers had levonorgestrel AUC 0-8h values similar to controls, while CYP2B6 poor metabolizers had AUC 0-8h values of 40% lower than controls. In the isoniazid-rifampin group, NAT2 rapid/intermediate acetylators had levonorgestrel AUC 0-8h values similar to controls, while NAT2 slow acetylators had AUC 0-8h values 36% higher than controls. CYP2B6 poor metabolizer genotypes exacerbate the efavirenz-levonorgestrel interaction, likely by increased CYP3A induction with higher efavirenz exposure, making the interaction more difficult to overcome. NAT2 slow acetylator genotypes attenuate the rifampin-levonorgestrel interaction, likely by increased CYP3A inhibition with higher isoniazid exposure.

Relevance of gene polymorphisms of NAT2 and NR1I2 to anti-tuberculosis drug-induced hepatotoxicity

The recommended treatment regimen for tuberculosis is a combination of agents with antitubercular activity, during which hepatotoxicity is one of the most common side effects. In addition to the N-acetyltransferase 2 (NAT2) genotype, rs3814055 in nuclear receptor subfamily 1, group I, member 2 (NR1I2) has been demonstrated to be associated with anti-tuberculosis drug-induced hepatotoxicity (ATDH), but previous results have been inconsistent. A retrospective nested hospital-based case–control study was performed to investigate the association between genetic polymorphisms and the risk of ATDH. Fifteen genetic variants (13 SNPs and two null genotypes) in cytochrome P450 2E1, NR1I2, UDP-glucuronosyltransferase 1A1, NAT2, superoxide dismutase 1, superoxide dismutase 2, and glutathione S-transferases (GSTT1, GSTM1, GSTP1) were genotyped. Odds ratios with 95% confidence intervals were calculated with drug doses, body mass index comorbidity of diabetes mellitus, and baseline alanine transaminase value as covariates. Conditional logistic regression demonstrated that the NAT2 slow acetylation genotype and the T allele of rs3814055 in NR1I2 may contribute to susceptibility to ATDH. Stratified association analysis demonstrated that in NAT2 non-slow acetylators, the T allele of rs3814055 was a risk factor for ATDH, whereas the T allele did not increase the susceptibility to ATDH in slow acetylators.

Occupational exposures and genetic susceptibility to lung cancer and pleural mesothelioma: a systematic review

&#x0D; Background&#x0D; The risk of occupationally related lung cancer, as well as pleural mesothelioma, in association with genetic polymorphisms, has been investigated with contradictory results.&#x0D; This systematic review aims to summarize the current knowledge on the relationship between genetic polymorphisms, occupational exposures, and lung cancer and pleural mesothelioma.&#x0D; Methods&#x0D; We searched MEDLINE, ISI Web of science, and SCOPUS online databases for all articles published in English language up to September 2016. Studies were considered eligible if they had assessed the association between occupational exposures and lung cancer/pleural mesothelioma in relation to genetic polymorphisms.&#x0D; Results&#x0D; Sixteen studies were included, of which eleven on lung cancer and six on mesothelioma, of which one was in common. NAT2 slow acetylator genotype confers an increased risk of pleural mesothelioma in subjects exposed to asbestos (OR=2.10; 95% CI=1.10-4.10), especially in combination with the GSTM1 null genotype (OR=3.60; 95% CI=1.30-9.60). GSTT1 null and CYP1A1 Msp1 T6235C (T/C+C/C) genotype carriers exposed to arsenic, uranium, asbestos and other chemical agents have an increased risk of lung cancer respect to not exposed wild type genotypes (OR=1.33; 95% CI=0.67-2.64, OR=2.20; 95% CI=1.11-4.35, respectively).&#x0D; Conclusion&#x0D; Genetic polymorphisms might modulate individual susceptibility to lung cancer and pleural mesothelioma in occupationally exposed subjects.&#x0D;

N-Acetyltransferase 2, Glutathione S-transferase gene polymorphisms and susceptibility to hepatocellular carcinoma in an Algerian population

ABSTRACT This study was conducted to investigate the potential association of genetic polymorphisms of glutathione S-transferase M1/T1 (GSTM1, GSTT1), and N-acetyltransferase 2 (NAT2) genes and epidemiological parameters with the risk of HCC in the Algerian population. A case-control study including 132 confirmed HCC patients and 141 cancer-free controls was performed. Genotyping analysis was performed using conventional multiplex PCR and PCR-RFLP. Statistical analysis was performed using the Chi-square test. Logistic regression analysis was used to estimate odds ratios and 95% confidence intervals (95% CI). GSTM1 null and NAT2 slow acetylator genotypes confer an increased risk to HCC (OR =1.88, 95% CI 1.16–3.05; OR =2.30, 95% CI 1.26–4.18, respectively). This association was prevalent in smokers (OR =2.00, 95% CI 1.05–3.8 and OR =2.55, 95% CI 1.22–5.34, respectively). No significant association was observed for GSTT1 null genotype in the contribution to HCC risk (OR =0.76, 95% CI 0.46–1.27). In conclusion, the GSTM1 and NAT2 gene polymorphisms are positively associated with the risk of HCC in older men and especially in smokers.

Homozygotes NAT2*5B slow acetylators are highly associated with hepatotoxicity induced by anti-tuberculosis drugs.

BACKGROUND Distinct N-acetyltransferase 2 (NAT2) slow acetylators genotypes have been associated with a higher risk to develop anti-tuberculosis drug-induced hepatotoxicity (DIH). However, studies have not pointed the relevance of different acetylation phenotypes presented by homozygotes and compound heterozygotes slow acetylators on a clinical basis.OBJECTIVES This study aimed to investigate the association between NAT2 genotypes and the risk of developing DIH in Brazilian patients undergoing tuberculosis treatment, focusing on the discrimination of homozygotes and compound heterozygotes slow acetylators.METHODS/FINDINGS The frequency of NAT2 genotypes was analysed by DNA sequencing in 162 patients undergoing tuberculosis therapy. The mutation analyses revealed 15 variants, plus two new NAT2 mutations, that computational simulations predicted to cause structural perturbations in the protein. The multivariate statistical analysis revealed that carriers of NAT2*5/*5 slow acetylator genotype presented a higher risk of developing anti-tuberculosis DIH, on a clinical basis, when compared to the compound heterozygotes presenting NAT2*5 and any other slow acetylator haplotype [aOR 4.97, 95% confidence interval (CI) 1.47-16.82, p = 0.01].CONCLUSION These findings suggest that patients with TB diagnosis who present the NAT2*5B/*5B genotype should be properly identified and more carefully monitored until treatment outcome in order to prevent the occurrence of anti-tuberculosis DIH.

Role of N-acetyltransferase 2 gene polymorphism in the human pathology

Nowadays multiple heterogeneous chemicals affect the human body. They include drugs, household chemicals, dyes, food supplements and others. The human organism can modify, inactivate, and eliminate the chemicals by biotransformation enzymes. But it is well known that biotransformation can lead to toxification phenomenon. Individuals differ from each other by the rate of chemical modification that promotes accumulation of toxins and carcinogens in some patients. An N-acetyltransferase 2 enzyme participates in the aromatic amines second phase metabolism. This work reviews the acetyltransferase gene polymorphism possible role in diseases development including drug-induced organs damage.Gene of acetyltransferase has polymorphisms associated with two haplotypes of fast and slow substrate acetylation. Gene alleles combine in three genotypes: fast, intermediate, and slow acetylators. Acetylation rate plays a significant role in side effects development during tuberculosis treatment and cancer pathogenesis. Recently, new data described the role of enzyme in development of non-infectious diseases in the human. Scientists consider that slow acetylation genotype in combination with high xenobiotic load result in accumulation of toxic substances able to damage cells.Therefore, acetyltransferase genotyping helps to reveal risk groups of cancer and non-infectious disease development and to prescribe more effective and safe doses of drugs.

15524 Ten of TEN and counting: The story of Toxic Epidermal Necrolysis (TEN) at the University of New Mexico from 2017 to 2018

Stevens-Johnson syndrome (SJS) and TEN are rare, acute, life-threatening mucocutaneous diseases often due to drug-induced immune-mediated epidermal necrosis. Associated symptoms include skin pain, fever, anxiety, and asthenia. Rashes initially appear benign but progress rapidly and unpredictably. Commonly affected populations include women, slow-acetylator genotypes, immunocompromised, and those treated with concurrent anticonvulsant and radiotherapy. High risk HLA types include B1502 in Asian/East Indians (carbamazepine) and B5801 in Han Chinese (allopurinol).

Association of slow acetylator genotype of N-acetyltransferase 2 with Parkinson’s disease in south Indian population

AimParkinson’s Disease (PD) is a neurodegenerative disorder with predisposing genetic and environmental factors. The present study was undertaken to elucidate the possible association of NAT2 gene polymorphism in PD patients from south India. MethodsUsing previously validated PCR-RFLP assays, we genotyped 105 PD subjects and 101 healthy controls for N-acetyl transferase (NAT2) gene polymorphism. ResultsWe observed a significantly elevated frequencies of NAT2 *5/6 (OR = 4.21; p < 0.029) and *5/7 (OR = 2.73; p < 0.025) genotypes and NAT2*5 (OR = 1.83; p < 0.039) allele among PD cases showing susceptible associations. The age at onset analysis revealed a significant association of NAT2 *4/6 (OR = 4.62; p < 0.05) genotype with early onset PD (EOPD). A positive association with early onset disease was observed for *5/7 (OR = 3.88; p < 0.075) genotype, however without statistical significance. Whereas, in late onset PD (LOPD) cases, significant susceptible association was observed for NAT2 *5/7 (OR = 5.27; p < 0.029) genotype. We observed a highly significant protective association of NAT2 *4/6 (OR = 0.27; p < 0.012) genotype and NAT2 *4 (OR = 0.52; p < 0.027) allele with LOPD. The acetylator status phenotype analysis have revealed a higher risk for, ‘NAT2 slow acetylator’ in both overall PD (OR = 2.39; p < 0.002) and LOPD (OR = 2.88; p < 0.007). However, ‘NAT2 intermediate acetylator’ with a lower risk in both overall PD (OR = 0.47; p < 0.011) and LOPD (OR = 0.36; p < 0.007) cases revealed protective associations. ConclusionsThus, our results revealed the possible susceptible association of NAT2 slow acetylator in PD pathogenesis in south Indian population.

Variability in the frequency of single nucleotide polymorphisms of N-acetyl transferase 2 (NAT2) gene among the different ethnic groups in Taiwan

Significant variations in the frequency of single nucleotide polymorphisms (SNPs) of human leukocyte antigen among Taiwan's aboriginal tribes and high homogeneity within each tribe have been reported. To identify variations in genetic polymorphisms of drug-metabolizing enzyme in seven of Taiwan's ethnic groups, the SNPs of N-acetyl transferase 2, a conjugation enzyme in phase II metabolism, were investigated. Methods: Three SNPs of NAT2, NAT2*5, NAT2*6, and NAT2*7, were determined by the TaqMan® method and subsequently confirmed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Our results showed statistically significant variations in the frequency of NAT2 genotype categories according to the 3 SNPs of NAT2 within 7 Taiwanese ethnic groups (Chi-square = 32.08, p<0.05). The distribution of the frequency of the slow acetylator genotype ranged from 32.0% in the Hakka population to 75.5% in the Paiwan population. A lack of NAT2*5 SNP alleles was found in the Atayal population, while a NAT2*5 allele frequency of 31.6% was observed in the Paiwan group. The frequencies of allele NAT2*6 and NAT2*7 in the investigated ethnic groups ranged from 11.2-37.0% and 17.0-53%, respectively. Our results also showed the considerable variations in drug-metabolizing enzyme NAT2 genotypes among Taiwan's aboriginal and general population. The variation in the genetic polymorphisms of drug-metabolizing enzyme in Taiwan's groups is worthy of further study to understand different therapeutic and adverse drug responses in ethnic groups.

N-acetyltransferase 2 acetylator genotype-dependent N-acetylation of 4-aminobiphenyl in cryopreserved human hepatocytes

Arylamine N-acetyltransferases are xenobiotic-metabolizing enzymes responsible for detoxification of many drugs and carcinogens. Two N-acetyltransferase proteins (NAT1 and NAT2) are expressed in humans and they both N-acetylate aromatic amine carcinogens such as 4-aminobiphenyl. Arylamines such as 4-aminobiphenyl represent a large class of chemical carcinogens. Exposure to 4-aminobiphenyl occurs in the chemical, dye and rubber industries as well as in hair dyes, paints, and cigarette smoke. NAT2 is subject to a genetic polymorphism resulting in rapid, intermediate and slow acetylator phenotypes. We investigated the role of the NAT2 genetic polymorphisms on the N-acetylation of 4-aminobiphenyl in cryopreserved human hepatocytes in which NAT2 genotype and deduced phenotype were determined. Differences in sulfamethazine (selectively N-acetylated via NAT2) and 4-aminobiphenyl (N-acetylated by both NAT1 and NAT2) N-acetylation rates among rapid, intermediate, and slow NAT2 acetylator genotypes were tested for significance by one-way analysis of variance. In vitro 4-aminobiphenyl N-acetyltransferase activities differed significantly between rapid, intermediate and slow acetylators at 10 µM (P = 0.0102) or 100 µM (P = 0.0028). N-acetylation of 4-aminobiphenyl in situ also differed significantly between human hepatocytes from rapid, intermediate, and slow acetylators at 10 µM (P = 0.0015) and 100 µM (P = 0.0216). A gene dose-response relationship was exhibited as intermediate acetylators catalyzed 4-aminobiphenyl N-acetylation both in vitro and in situ at rates arithmetically between rapid and slow acetylators. In conclusion, N-acetylation of 4-aminobiphenyl is NAT2 genotype-dependent in human hepatocytes. These results suggest refinement of the exposure limit and safety for arylamine carcinogens according to NAT2 genotype.

N-Acetyltransferase 2 Genotypes among Zulu-Speaking South Africans and Isoniazid and N-Acetyl-Isoniazid Pharmacokinetics during Antituberculosis Treatment.

The distribution of N-acetyltransferase 2 gene (NAT2) polymorphisms varies considerably among different ethnic groups. Information on NAT2 single-nucleotide polymorphisms in the South African population is limited. We investigated NAT2 polymorphisms and their effect on isoniazid pharmacokinetics (PK) in Zulu black HIV-infected South Africans in Durban, South Africa. HIV-infected participants with culture-confirmed pulmonary tuberculosis (TB) were enrolled from two unrelated studies. Participants with culture-confirmed pulmonary TB were genotyped for the NAT2 polymorphisms 282C>T, 341T>C, 481C>T, 857G>A, 590G>A, and 803A>G using Life Technologies prevalidated TaqMan assays (Life Technologies, Paisley, UK). Participants underwent sampling for determination of plasma isoniazid and N-acetyl-isoniazid concentrations. Among the 120 patients, 63/120 (52.5%) were slow metabolizers (NAT2*5/*5), 43/120 (35.8%) had an intermediate metabolism genotype (NAT2*5/12), and 12/120 (11.7%) had a rapid metabolism genotype (NAT2*4/*11, NAT2*11/12, and NAT2*12/12). The NAT2 alleles evaluated in this study were *4, *5C, *5D, *5E, *5J, *5K, *5KA, *5T, *11A, *12A/12C, and *12M. NAT2*5 was the most frequent allele (70.4%), followed by NAT2*12 (27.9%). Fifty-eight of 60 participants in study 1 had PK results. The median area under the concentration-time curve from 0 to infinity (AUC0-∞) was 5.53 (interquartile range [IQR], 3.63 to 9.12 μg h/ml), and the maximum concentration (Cmax) was 1.47 μg/ml (IQR, 1.14 to 1.89 μg/ml). Thirty-four of 40 participants in study 2 had both PK results and NAT2 genotyping results. The median AUC0-∞ was 10.76 μg·h/ml (IQR, 8.24 to 28.96 μg·h/ml), and the Cmax was 3.14 μg/ml (IQR, 2.39 to 4.34 μg/ml). Individual polymorphisms were not equally distributed, with some being represented in small numbers. The genotype did not correlate with the phenotype, with those with a rapid acetylator genotype showing higher AUC0-∞ values than those with a slow acetylator genotype, but the difference was not significant (P = 0.43). There was a high prevalence of slow acetylator genotypes, followed by intermediate and then rapid acetylator genotypes. The poor concordance between genotype and phenotype suggests that other factors or genetic loci influence isoniazid metabolism, and these warrant further investigation in this population.

A case series of three patients presenting with isoniazid induced toxicity and N-acetyl transferase 2 gene mutation: A management conundrum for programmatic therapy of tuberculosis in India

Isoniazid is an essential drug in the management of tuberculosis but there is a high degree of variation in the Indian population's capacity to acetylate or inactivate isoniazid to the inactive metabolite acetyl isoniazid, and they can be distinctly characterized phenotypically as being either slow or rapid inactivators (the concentration of the enzyme being higher in rapid inactivators). Several mutations in the N-acetyl transference 2 (NAT2) gene account for majority of the slow acetylator genotypes in the human population (NAT2*5A, NAT2*5B, and NAT2*6A). Such individuals are at a greater risk of drug-induced adverse reactions due to reduced drug elimination, compared to those possessing the wild type allele. Here we discuss two cases of Isoniazid induced peripheral neuropathy and one case of Isoniazid induced hepatotoxicity confirmed as having heterozygous or homozygous NAT2 gene mutation. In all 3 cases, the presence of NAT2 gene mutation was associated with the adverse events and the adverse events subsided on stopping or reducing the dose of isoniazid. However, due to lack of guideline-based management of adverse events occurring due to isoniazid, the drug was either abruptly stopped or dosage lowered based only on clinical expertise, which could potentially lead to further resistance to Mycobacterium tuberculosis (as occurred in one of our cases). Further studies of the relationship between NAT2 genotypes, isoniazid concentrations and adverse drug events are required to make genotyping a helpful tool for optimizing isoniazid's therapeutic response and minimizing adverse drug reactions, particularly in countries with a high burden of tuberculosis.

Is NAT2 Gene Polymorphism Associated with Vitiligo?

Background:N-acetyltransferase-2 (NAT2) is a phase II xenobiotic enzyme that plays an important role against oxidative stress-mediated reactive oxygen species protection. Polymorphism in specific genotypes of NAT2 may lead to increase an imbalance in antioxidant systems and may influence the pathogenesis of vitiligo. We conducted this study to see the association between NAT2 gene polymorphism and risk of vitiligo. We looked into whether single-nucleotide polymorphisms (SNP) at positions 857, 481 and 590 of the coding region of the NAT2 gene play as a risk factor for vitiligo among north Indian people.Methods:In this study, we assessed 100 patients with vitiligo and 160 healthy individuals as controls. Genomic DNA was extracted from human peripheral blood and polymerase chain reaction–restricted fragment length polymorphism was done to identify the single nucleotide polymorphism at positions 857, 481, and 590 of the coding region of the NAT2 gene.Results:In this study, we observed a significant higher risk with slow acetylator genotypes of NAT2 (OR = 2.85; 95% CI = 1.68-4.84, P value < 0.001) for the vitiligo. Furthermore, in the association between NAT2 acetylator genotypes with percentage of body surface area (BSA) of disease, we observed that slow acetylator genotypes of NAT2 has significant higher risk with low grade of disease (1%–10% >11%–30% >30% of BSA).Limitations:A major limitation of this study was the small sample size and warrants further investigation on a large epidemiological study to confirm these findings.Conclusions:Our preliminary data indicate that NAT2 slow acetylator genotype exhibits significant association for the risk of vitiligo, especially in disease predisposition and initiation.

Association of genetic polymorphisms of CYP2E1, NAT2, GST and SLCO1B1 with the risk of anti-tuberculosis drug-induced liver injury: a systematic review and meta-analysis

ObjectivesThe objective of this study was to investigate the association between genetic polymorphisms of N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), glutathione S-transferase (GST) and solute carrier organic anion transporter...

N-acetyltransferase 2 polymorphism and acetylation profiles in Buginese ethnics of Indonesia.

N-acetyltransferase 2 (NAT2) is a key enzyme involved in the phase II metabolism of aromatic amines and heterocyclic aromatic amines present in a wide range of xenobiotics. The aim of this study was to investigate the NAT2 polymorphism in the Buginese ethnic group of Indonesia to determine the frequency of NAT2 alleles in this population. We found six haplotypes consisting of six single-nucleotide polymorphisms and 12 NAT2 genotype variations. NAT2*6A haplotype (42%) showed the highest frequency, followed by NAT2*4 (33%), NAT2*7B (15%), NAT2*5B (5%), NAT2*12A (3%), and NAT2*13 (2%). In terms of phenotypes, the Buginese population comprised 18% rapid acetylators, 40% intermediate acetylators, and 42% slow acetylators. We confirmed the high-frequency slow acetylator phenotype in the Buginese population. The NAT2*6A/*6A genotype was the most frequent slow acetylator genotype, followed by NAT2*6A/*7B. The pattern of NAT2 alleles of Buginese is similar to Southeast Asian populations but not Northeast Asian populations. However, the slow acetylator frequencies in the Buginese population were higher than those in Northeast Asian populations and lower than those in Caucasians and some American populations.

Association of Nat2 Gene Polymorphism with Antitubercular Drug-induced Hepatotoxicity in the Eastern Uttar Pradesh Population.

IntroductionTuberculosis (TB) remains an important cause of morbidity and mortality worldwide. There are more than 20 drugs available for TB treatment. Hepatotoxicity is the most serious adverse drug reaction of anti-TB drugs. Various pathogenesis and genetic factors are associated with antituberculosis drug-induced hepatotoxicity (ATDIH). Antituberculosis drugs (ATDs) are mostly metabolized by N-acetyltransferase 2 (NAT2). Therefore, in this study, we aim to evaluate the role of the NAT2 genotype in ATDIH in the eastern Uttar Pradesh population.MethodsA total of 100 TB patients who had been treated with anti-TB drugs were enrolled in this studied. In this group, 70 TB patients did not develop drug-induced hepatotoxicity (tolerant control group) and 30 TB patients developed ATDIH (ATDIH group). The genetic polymorphisms of the NAT2 genes were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotype and allele frequencies were evaluated by the t-test and odds ratio (OR) with 95% confidence intervals (CIs) were used to evaluate the strength of the associations.ResultsThere is a high percentage of slow acetylators in the Eastern Uttar Pradesh population. Four percent of people are fast acetylators, 34% are intermediate acetylators, and 62% are slow acetylators. The frequency of slow acetylators in the NAT2 genotype was commonly present and was not significantly different between the ATDIH (73.33%) and tolerant control groups (61.40%). However, the genotypic distribution of variants of slow-acetylator genotypes (NAT2*6/7, NAT2*5/7, and NAT2*5/6) was also not significantly different in ATDIH.ConclusionIn the present study, the slow acetylators of the NAT2 genotype did not contribute to the elevated risk of ATDIH development in tuberculosis patients.

NAT2 ultra-slow acetylator and risk of anti-tuberculosis drug-induced liver injury: a genotype-based meta-analysis.

NAT2 slow acetylator is a confirmed risk of anti-tuberculosis drug-induced liver injury (ATDILI). However, NAT2 ultra-slow acetylators, a new refinement among NAT2 slow acetylators, have been recently proposed. The patients with NAT2 genotypes of *6A/*6A, *6A/*7B and *7B/*7B are referred to in this group. We aim to prove an association of the NAT2 ultra-slow acetylators with the risk of ATDILI. Systematic review and meta-analysis were performed based on each NAT2 genotype and risk of ATDILI cases and also new classification of the ultra-slow acetylators up to 31 October 2016. Meta-analysis of 18 studies with 822 ATDILI cases and 4630 controls was carried out in the RevMan software, version 5.3 with fixed-effect (low heterogeneity) and random effect (moderate to high heterogeneity) methods. The strong associations between each NAT2 slow acetylator genotypes and ATDILI were confirmed in meta-analysis except for NAT2*5B/*5B [odds ratio (OR): 1.69; 95% confidence interval (CI): 0.96-2.95; P=0.0679]. The NAT2 ultra-slow acetylators contribute to higher risk of ATDILI (OR: 3.60; 95% CI: 2.30-5.63; P=1.76E-08) than all NAT2 slow acetylators (OR: 2.80; 95% CI: 2.20-3.57; P=5.73E-18) as well as fast acetylators. Additional in-vitro study using isoniazid as a substrate supports the existence of ultra-slow acetylator alleles (NAT2*6A and NAT2*7B). This is the first meta-analysis of NAT2 and the risk of ATDILI at the genotypic level. The result demonstrated that NAT2 ultra-slow acetylator genotypes will have the most effect on the increased risk of ATDILI.