High-Resolution HLA Typing of HLA-A, -B, -C, -DRB1, and -DQB1 in Kinh Vietnamese by Using Next-Generation Sequencing

Analysis of PROC mutations and clinical features in 22 unrelated families with inherited protein C deficiency

Currently, limited information is available in the literature regarding the relationships between PROC mutations and clinical features in Chinese individuals. We aimed to characterize severe congenital Protein C deficiency in 22 unrelated Chinese families in a tertiary hospital by analyzing its clinical manifestation, associated risk factors, and gene mutations. We measured protein C activity and antigen levels for all participants, screened them for mutations in the PROC gene, and analyzed the clinical features of each family to identify commonalities and differences. The analysis revealed a total of 75 individuals with PCD and 16 different PROC mutations, including 12 missense mutations and 4 deletion mutations. Among them, 11 who were compound heterozygotes or homozygotes for mutations tended to develop symptoms at a younger age without any clear triggers. In contrast, the remaining 64 individuals who were heterozygotes for mutations often had clear triggers for their symptoms and experienced a milder course of the disease. It is worth noting that the mutation c.565C > T occurred most frequently, being identified in 8 out of 22 families (36%). Our team also reported five novel mutations, including c.742-744delAAG, c.383G > A, c.997G > A, c.1318C > T, and c.833T > C mutations. The identification of five novel mutations adds to the richness of the Human Genome Database. Asymptomatic heterozygotes are not uncommon, and they are prone to develop symptoms with obvious triggers. The evidence presented strongly suggest that asymptomatic individuals with family history of protein C deficiency can benefit from mutational analysis of PROC gene.

PGT-HLA programmes for the cure of a sick sibling: clinical strategies for this challenging search

The ultimate goal of a preimplantation genetic testing and human leukocyte antigen (PGT-HLA) matching programme is the birth of a healthy, HLA-compatible child for the treatment or cure of a sick sibling. Several authors have published successful cases of the births of children HLA-matched to siblings affected by different conditions and diseases. However, there are many reports of failed attempts. Couples seeking an HLA-matched sibling for their affected child look for positive outcomes in the shortest possible time. Nevertheless, there is no published consensus or guidelines with recommendations for these cases. Here, the authors aimed to analyse different approaches for these programmes, highlighting the most promising strategies for the families and fertility units. Furthermore, the authors mention a successful case of a PGT-HLA matching programme after a previous failed attempt following the strategies proposed. Which is the most cost-effective and time-efficient approach in a PGT-HLA matching programme?

The genotype list string code syntax for exchanging nomenclature-level genotyping results in clinical and research data management and analysis systems

The nomenclatures used to describe HLA and killer-cell immunoglobulin-like receptor (KIR) alleles distinguish unique nucleotide and peptide sequences, and patterns of expression, but are insufficient for describing genotyping results, as description of ambiguities and relations across loci require terminology beyond allele names. The genotype list (GL) String grammar describes genotyping results for genetic systems with defined nomenclatures, like HLA and KIR, documenting what is known and unknown about a given genotyping result. However, the accuracy of a GL String is dependent on the reference database version under which it was generated. Here, we describe the GL string code (GLSC) system, which associates each GL String with meta-data describing the specific reference context in which the GL String was created, and in which it should be interpreted. GLSC is a defined syntax for exchanging GL Strings in the context of a specific gene-family namespace, allele-name code-system, and pertinent reference database version. GLSC allows HLA and KIR genotyping data to be transmitted, parsed and interpreted in the appropriate context, in an unambiguous manner, on modern data-systems, including Health Level 7 Fast Healthcare Interoperability Resource systems. Technical specification for GLSC can be found at https://glstring.org.

The pharmacogenomics of carbamazepine-induced cutaneous adverse drug reaction in the South of Vietnam

Background: The relationship between HLA-B*15:02 and Severe Cutaneous Adverse Reactions was rigorously examined in Japanese, Han Chinese, Thais, and Caucasians. However, the number of studies about this topic in Vietnamese population is still limited and mostly focuses on the North of Vietnam. Objective: This study aims to clarify the genetic culprit of SCARs in Vietnamese population, particularly in the South of Vietnam, and to validate our result by a meta-analysis about this topic in Vietnamese. Method: A retrospective case-control study with 37 patients treated with carbamazepine monotherapy. Statistical calculation and meta-analysis were performed by R software. Result: HLA-B*15:02 increases the risk of SJS 12.5 times higher in CBZ-treated patients (p-value = 0.017). However, this allele has no impact on MCARs (Mild Cutaneous Adverse Reactions) of CBZ. The number needed to test and the number needed to genotype is two and nine patients respectively. Conclusion: This study recommends more investigations about the cost-effectiveness of this test to accelerate the protection of Southern Vietnamese from SCARs.

Design and generation of mRNAs encoding conserved regions of SARS-CoV-2 ORF1ab for T cell-mediated immune activation

Aim

To generate mRNAs encoding conserved regions within SARS-CoV-2 ORF1ab which can induce strong T-cell responses to overcome the immune invasion of newly emergent variants.

Methods

We selected two conserved regions with a high density of T-cell epitopes using immunoinformatics for mRNA synthesis. The ability of testing mRNAs to activate T cells for IFN-γ production was examined by an ELISpot assay and flow cytometry.

Results

Two synthesized mRNAs were successfully translated in MDA-MB-231 cells and had comparable potency to the spike mRNA to induce CD4+ and CD8+ T-cell responses in peripheral blood mononuclear cells in 29 out of 34 participants.

Conclusion

This study provides a proof-of-concept for the use of SARS-CoV-2 conserved regions to develop booster vaccines capable of eliciting T-cell-mediated immunity.

Allele and haplotype frequencies of 11 HLA loci in Koreans by next-generation sequencing

Data on HLA genotype distribution, including DQA1 and DPA1, in the Korean population are limited. We aimed to investigate the allele and haplotype frequencies of 11 HLA loci in 339 Korean subjects using next-generation sequencing (NGS)-based HLA typing. A total of 339 samples from unrelated healthy subjects were genotyped for HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1, -DQA1, -DPB1, and -DPA1 using two different NGS-based HLA typing kits (166 tested using the NGSgo-MX11-3 kit [GenDx, Netherlands] and 173 by the AllType NGS 11 Loci Amplification kit [One Lambda, USA]). PyPop software was used to estimate allele and haplotype frequencies and linkage disequilibrium between the loci. Additionally, a principal component analysis was performed to compare the allele distribution of Koreans with that of other populations. A total of 214 HLA alleles (97 class I and 117 class II alleles) were assigned. The most frequent alleles for each locus were A*24:02:01 (24.78%), B*15:01:01 (10.18%), C*01:02:01 (18.44%), DRB1*04:05:01 (9.59%), DRB3*02:02:01 (13.72%), DRB4*01:03:01 (25.81%), DRB5*01:01:01 (9.0%), DQA1*01:02:01 (16.96%), DQB1*03:01:01 (14.31%), DPA1*01:03:01 (44.4%), and DPB1*05:01:01 (35.1%), respectively. The most frequent haplotypes were A*33:03:01-C*03:02:02-B*58:01:01 for HLA class I (5.01%) and DRB1*04:05:01-DQA1*03:03:01-DQB1*04:01:01-DPA1*02:02:02-DPB1*05:01:01 for HLA class II (6.23%). The total allelic ambiguities by NGS were estimated to be minimal and considerably decreased compared with those by Sanger sequencing. The Japanese population had the most similar allele distribution to Koreans, followed by the Chinese population. Frequency data of 11 HLA loci in Koreans can provide essential data for population genetics and disease association studies.

Clinical and genetic analysis of Vietnamese patients diagnosed with early-onset Parkinson's disease

BACKGROUND

Genetic factors play a crucial role in the pathogenesis of Parkinson's disease (PD). However, no comprehensive study has described genetic alterations in Vietnamese patients diagnosed with PD. This study aimed to identify genetic causes and their association with clinical phenotypes in a Vietnamese PD cohort.

METHODS

A total of 83 patients with early-onset PD (disease onset before the age of 50) were recruited for genetic analysis using a combination of multiplex ligation-dependent probe amplification and next-generation sequencing for a panel of 20 PD-associated genes.

RESULTS

It was found that 37 out of 83 patients carried genetic alterations, with 24 pathogenic/likely pathogenic/risk variants and 25 variants of uncertain significance. The pathogenic/likely pathogenic/risk variants were mostly detected in LRRK2, PRKN, and GBA, while the variants of uncertain significance were identified in 12 different genes that were studied. The most common genetic alteration was LRRK2 c.4883G>C (p.Arg1628Pro), and patients with PD carrying this variant were found to have a distinct phenotype. Participants carrying pathogenic/likely pathogenic/risk variants had a significantly higher rate of a family history of PD.

CONCLUSION

These results provide a further understanding of genetic alterations associated with PD in a South-East Asian population.

HLA types and their association with end-stage renal disease in Vietnamese patients: A cross-sectional study

End-stage renal disease (ESRD) is a significant public health issue with an estimated increasing burden over the next 10 years. Early prediction of patients with a high risk of ESRD progression is crucial to monitor and initiate appropriate interventions, of which HLA alleles have been proposed as promising biomarkers. This cross-sectional study described HLA profiles of a Vietnamese cohort and investigated the association between HLA alleles and ESRD. All ESRD patients who were waitlisted to receive kidney transplant and potential donors in a tertiary hospital from March 2018 to April 2020 were invited to participate in the study. A total of 458 participants were eligible, including 126 ESRD patients and 126 family-related donors, 98 ESRD patients and 108 unrelated donors. HLA typing was performed using Luminex-based PCR-SSO technology. We found HLA-A*02, A*11, A*24, B*15, B*07, DRB1*12, DRB1*09, DQA1*01, DQA1*06, DQB1*03 and DQB1*05 as the most common alleles, which is similar to the general Vietnamese population and other countries in East and South-east Asia. HLA-B*07 (P = .040), DQA1*06 (P = .031), and DQB1*03 (P = .036) were susceptible to ESRD, while HLA-B*27 (P = .024) and DQB1*02 (P = .006) were associated with a decreased risk of ESRD.

Allopurinol-induced Stevens-Johnson syndrome and toxic epidermal necrolysis: Signal detection and preventability from Vietnam National pharmacovigilance database

WHAT IS KNOWN AND OBJECTIVE

Allopurinol, the first-line medication for hyperuricemia is well-known for its association with severe cutaneous adverse reactions, especially Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). In the current study, we analysed the Vietnamese spontaneous reporting database to identify signals and preventability of allopurinol-induced SJS/TEN in Vietnam from 2010 to 2019.

METHODS

Signal generation was assessed using the case/non-case method. Reporting odds ratios (RORs) and 95% confidence intervals (95% CI) were calculated.

RESULTS

Among 72,822 spontaneous ADR reports submitted to the Vietnam National Drug Information and Adverse Drug Reaction Monitoring Centre, 392 reports were on SJS/TEN, of which, 65 cases (16.6%) were related to allopurinol. The signals of allopurinol-induced SJS/TEN in Vietnam started in 2014 (ROR of 3.531, 95% CI: 1.830-6.810) and annually increased until 2019 (ROR of 11.923, 95% CI: 8.508-16.710). The preventability assessment showed that no allopurinol-induced SJS/TEN case was definitely unpreventable. 61.6% of the SJS/TEN cases were avoidable because they were associated with inappropriate prescribing such as unapproved indications, too high initial dose and even rechallenging in patients with a history of allopurinol allergy.

WHAT IS NEW AND CONCLUSION

The signals of allopurinol-induced SJS/TEN in Vietnam started in 2014 and annually increased until 2019. Our first report specifically focusing on the ADR preventability of allopurinol showed that correction of medical errors relating to prescription could prevent more than 60% of SJS/TEN cases in Vietnamese allopurinol users. This is a feasible and practical solution, provided that there would be a systematic change in both healthcare systems and public awareness.

Genotype-phenotype characteristics of Vietnamese patients diagnosed with Charcot-Marie-Tooth disease

BACKGROUND

Charcot-Marie-Tooth (CMT) disease is one of the most common hereditary neuropathies. Identifying causative mutations in CMT is essential as it provides important information for genetic diagnosis and counseling. However, genetic information of Vietnamese patients diagnosed with CMT is currently not available.

METHODS

In this study, we described the clinical profile and determined the mutation spectrum of CMT in a cohort of Vietnamese patients with CMT by using a combination of multiplex ligation-dependent probe amplification and next-generation sequencing targeting 11 genes PMP22, MPZ, EGR2, NEFL, MFN2, GDAP1, GARS, MTMR2, GJB1, RAB7A, LITAF.

RESULTS

In 31 CMT cases, the mutation detection rate was 42% and the most common genetic aberration was PMP22 duplication. The pedigree analysis showed two de novo mutations c.64C > A (p.P22T) and c.281delG (p.G94Afs*17) in the NEFL and PMP22 genes, respectively.

CONCLUSION

The results of this study once again emphasize the important role of molecular diagnosis and provide preliminary genetic data on Vietnamese patients with CMT.

Frequency and distribution of HLA-DQB1 alleles from 2076 cord blood samples of the Vietnamese cohort

Human leucocyte antigen (HLA) alleles are very diverse and characterized by ethnicity. To date, information about the frequencies and distributions of HLA alleles among the Vietnamese population is still limited. In this study, HLA-DQB1 alleles of 2076 cord blood units from individuals belonging to Vietnam's Kinh ethnic people were genotyped using Luminex-based polymerase chain reaction sequence-specific oligonucleotide. The results of the study demonstrated that there were 23 alleles on the locus HLA-DQB1. Among those, there were six alleles with high frequencies of over 5%, including DQB1^* 03:01 (35.9%), DQB1^* 05:01 (12.8%), DQB1^* 03:03 (12.2%); DQB1^* 06:01 (7.20%), DQB1^* 05:02 (6.62%) and DQB1^* 02:01 (5.30%) and five rare alleles with low frequencies of below 0.1%. More importantly, this study for the first time reported the presence of two new rare alleles including DQB1^* 01:01 and DQB1^* 01:02. Conclusively, this study provided significant information about HLA-DQB1 alleles for further investigations and clinical applications.

Allele and Haplotype Frequencies of HLA-A, -B, -C, and -DRB1 Genes in 3,750 Cord Blood Units From a Kinh Vietnamese Population

The frequencies and diversities of human leukocyte antigen (HLA) alleles and haplotypes are representative of ethnicities. Matching HLA alleles is essential for many clinical applications, including blood transfusion, stem cell transplantation, and tissue/organ transplantation. To date, the information about the frequencies and distributions of HLA alleles and haplotypes among the Kinh Vietnamese population is limited because of the small sample size. In this study, more than 3,750 cord blood units from individuals belonging to the Kinh Vietnamese population were genotyped using PCR sequence-specific oligonucleotide (PCR-SSO) for HLA testing. The results of the study demonstrated that the most frequently occurring HLA-A, -B, -C, and -DRB1 alleles were A*11:01 (25%), A*24:02 (12.3%), A*02:01 (11.2); A*03:03 (8.95%), A*02:03 (7.81%), A*29:01 (7.03%); B*15:02 (15.1%), B*46:01 (10.7%), B*58:01 (7.65%), B*38:02 (7.29%); C*08:01 (17.2), C*07:02 (16.2%), C*01:02 (15.2), C*03:02 (8.3%), C*15:05 (6.13); DRB1*12:02 (31.0%), DRB1*09:01 (10.47%), DRB1*15:02 (7.54%); DRB1*07:01 (6.68%), DRB1*10:01 (6.63%), respectively, with the highest allele diversity level observed in locus B (93 alleles). The most frequent haplotypes of two-locus combinations of HLA-A–B, HLA-A–C, HLA-A–DRB1, HLA-B–C, HLA-B–DRB1, and HLA-C–DRB1 haplotypes were A*11:01–B*15:02 (7.63%), A*11:01–C*08:01 (7.98%), A*11:01–DRB1*12:02 (10.56%), B*15:02–C*08:01 (14.0%), B*15:02–DRB1*12:02 (10.47%), and C*08:01–DRB1*12:02 (11.38%), respectively. In addition, the most frequent haplotypes of three- and four-locus sets of HLA-A–B–C, HLA-A–B–DRB1, HLA-A–C–DRB1, HLA-B–C–DRB1, and HLA-A–B–C–DRB1 were A*11:01–B*15:02–C*08:01 (7.57%), A*11:01–B*15:02–DRB1*12:02 (5.39%), A*11:01–C*08:01–DRB1*12:02 (5.54%), B*15:02–C*08:01–DRB1*12:02 (10.21%), and A*11:01–B*15:02–C*08:01–DRB1*12:02 (5.45%), respectively. This study provides critical information on the frequencies and distributions of HLA alleles and haplotypes in the Kinh Vietnamese population, accounting for more than 85% of Vietnamese citizens. It paves the way to establish an umbilical cord blood bank for cord blood transplantation programs in Vietnam.

Human Leukocyte Antigen (HLA) System: Genetics and Association with Bacterial and Viral Infections

The human leukocyte antigen (HLA) system is one of the most crucial host factors influencing disease progression in bacterial and viral infections. This review provides the basic concepts of the structure and function of HLA molecules in humans. Here, we highlight the main findings on the associations between HLA class I and class II alleles and susceptibility to important infectious diseases such as tuberculosis, leprosy, melioidosis, Staphylococcus aureus infection, human immunodeficiency virus infection, coronavirus disease 2019, hepatitis B, and hepatitis C in populations worldwide. Finally, we discuss challenges in HLA typing to predict disease outcomes in clinical implementation. Evaluation of the impact of HLA variants on the outcome of bacterial and viral infections would improve the understanding of pathogenesis and identify those at risk from infectious diseases in distinct populations and may improve the individual treatment.

Allopurinol-induced severe cutaneous adverse reactions in Vietnamese: the role of HLA alleles and other risk factors

Aim: To reveal the association of three class I HLA alleles, including HLA-A*33:03, HLA-B*58:01 and HLA-C*03:02, and allopurinol-induced severe cutaneous adverse reactions (SCARs) in Vietnamese patients. Methods: A case–control study on 100 allopurinol-induced SCARs patients, 183 tolerant controls and 810 population controls was performed. The HLA-A*33:03 and HLA-C*03:02 alleles were detected with the nested allele-specific PCR method; the HLA-B*58:01 allele was detected with the sequence-specific primer PCR method. Results: There were strong associations between HLA-B*58:01 and HLA-C*03:02 and allopurinol-induced SCARs. Specific associations were found between HLA-B*58:01 and Stevens–Johnson syndrome/toxic epidermal necrolysis and between HLA-C*03:02 and drug reaction with eosinophilia and systemic symptoms, with a gene dosage effect. The multivariate regression analysis indicated two significant independent risk factors: HLA-B*58:01/HLA-C*03:02 and estimated glomerular filtration rate <60 ml/min/1.73 m2. The specificity, positive predictive value and negative predictive value of HLA-B*58:01 testing were higher than the HLA-C*03:02 or the multiplex testing, especially in patients with impaired renal function. Conclusion: The results supported pre-treatment HLA-B*58:01 testing in Vietnamese patients with declined renal function to prevent SCARs.

Molecular characteristics of young-onset colorectal cancer in Vietnamese patients

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancer globally. Understanding the genetic characteristics of CRC is essential for appropriate treatment and genetic counseling.

METHODS

The genetic profile of CRC tumor tissues was identified using next-generation sequencing of 17 target genes (MLH1, MSH2, MSH6, PMS2, EPCAM, APC, SMAD4, BMPR1A, MUTYH, STK11, PTEN, TP53, ATM, CDH1, CHEK2, POLE, and POLD1) in a cohort of 101 Vietnamese patients diagnosed with young-onset CRC. Corresponding germline genetic alterations of determined somatic mutations were subsequently confirmed from patients' blood samples.

RESULTS

Somatic mutations were determined in 96 out of 101 CRC patients. Two-thirds of the tumors harbored more than two mutations, and the most prevalent mutated genes were TP53 and APC. Among confirmed germline mutations, 10 pathogenic mutations and 11 variants of unknown significance were identified.

CONCLUSIONS

Given the burden of CRC and the gradually reducing cost of genetic testing, multigene panel screening can benefit young-onset CRC patients as well as their relatives.

Association of ADIPOQ Single-Nucleotide Polymorphisms with the Two Clinical Phenotypes Type 2 Diabetes Mellitus and Metabolic Syndrome in a Kinh Vietnamese Population

PURPOSE

Genetic factors play an important role in the development of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). However, few genetic association studies related to these disorders have been performed with Vietnamese subjects. In this study, the potential associations of ADIPOQ single nucleotide polymorphisms (SNPs) with T2DM and MetS in a Kinh Vietnamese population were investigated.

PATIENTS AND METHODS

A study with 768 subjects was conducted to examine the associations of four ADIPOQ SNPs (rs266729, rs1501299, rs3774261, and rs822393) primarily with T2DM and secondarily with MetS. The TaqMan SNP genotyping assay was used to determine genotypes from subjects' DNA samples.

RESULTS

After statistical adjustment for age, sex, and body mass index, the ADIPOQ SNP rs266729 was found to be associated with increased risk of T2DM under multiple inheritance models: codominant (OR = 2.30, 95% CI = 1.16-4.58), recessive (OR = 2.17, 95% CI = 1.11-4.26), and log-additive (OR = 1.32, 95% CI = 1.02-1.70). However, rs1501299, rs3774261, and rs822393 were not associated with risk for T2DM. Additionally, rs266729, rs3774261, and rs822393 were statistically associated with MetS, while rs1501299 was not. Haplotype analysis showed a strong linkage disequilibrium between the SNP pairs rs266729/rs822393 and rs1501299/rs3774261, and the haplotype rs266729(G)/rs822393(T) was not statistically associated with MetS.

CONCLUSION

The results show that rs266729 is a lead candidate SNP associated with increased risk of developing T2DM and MetS in a Kinh Vietnamese population, while rs3774261 is associated with MetS only. Further functional characterization is needed to uncover the mechanism underlying the potential genotype-phenotype associations.

Allele and haplotype frequencies of human leukocyte antigen-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1, and -DPB1 by next generation sequencing-based typing in Koreans in South Korea

Allele frequencies and haplotype frequencies of HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1, and -DPB1 have been rarely reported in South Koreans using unambiguous, phase-resolved next generation DNA sequencing. In this study, HLA typing of 11 loci in 173 healthy South Koreans were performed using next generation DNA sequencing with long-range PCR, TruSight^® HLA v2 kit, Illumina MiSeqDx platform system, and Assign^™ for TruSight^™ HLA software. Haplotype frequencies were calculated using the PyPop software. Direct counting methods were used to investigate the association with DRB1 for samples with only one copy of a particular secondary DRB locus. We compared these allele types with the ambiguous allele combinations of the IPD-IMGT/HLA database. We identified 20, 40, 26, 31, 19, 16, 4, and 16 alleles of HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQA1, HLA-DQB1, HLA-DPA1, and HLA-DPB1, respectively. The number of HLA-DRB3/4/5 alleles was 4, 5, and 3, respectively. The haplotype frequencies of most common haplotypes were as follows: A*33:03:01-B*44:03:01-C*14:03-DRB1*13:02:01-DQB1*06:04:01-DPB1*04:01:01 (2.89%), A*33:03:01-B*44:03:01-C*14:03 (4.91%), DRB1*08:03:02-DQA1*01:03:01-DQB1*06:01:01-DPA1*02:02:02-DPB1*05:01:01 (5.41%), DRB1*04:05:01-DRB4*01:03:01 (12.72%), DQA1*01:03:01-DQB1*06:01:01 (13.01%), and DPA1*02:02:02-DPB1*05:01:01 (30.83%). In samples with only one copy of a specific secondary DRB locus, we examined its association with DRB1. We, thus, resolved 10 allele ambiguities in HLA-B, -C (each exon 2+3), -DRB1, -DQB1, -DQA1, and -DPB1 (each exon 2) of the IPD-IMGT/HLA database. Korean population was geographically close to Japanese and Han Chinese populations in the genetic distances by multidimensional scaling (MDS) plots. The information obtained by HLA typing of the 11 extended loci by next generation sequencing may be useful for more exact diagnostic tests on various transplantations and the genetic population relationship studies in South Koreans.

Association Between AGT M235T and Left Ventricular Mass in Vietnamese Patients Diagnosed With Essential Hypertension

Background: Increasing left ventricular mass in hypertensive patients is an independent prognostic marker for adverse cardiovascular outcomes. Genetic factors have been shown to critically affect left ventricular mass. AGT M235T is one of the genetic polymorphisms that may influence left ventricular mass due to its pivotal role in the regulation of plasma angiotensinogen level as well as hypertension pathophysiology in Asian populations. Currently, how M235T affects left ventricular mass is not well-described in Vietnamese hypertensive patients. This study aimed to investigate the association between M235T and left ventricular mass in Vietnamese patients diagnosed with essential hypertension.

Materials and Methods:AGT M235T genotyping and 2D echocardiography were performed on 187 Vietnamese subjects with essential hypertension. All the ultrasound parameters were obtained to calculate the left ventricular mass index according to the American Society of Echocardiography and the European Association of Cardiovascular Imaging 2015 guidelines. Other clinical characteristics were also recorded, including age, gender, duration of hypertension, hypertensive treatment, lifestyle, renal function, fasting plasma glucose, and lipid profile.

Results: MT and TT genotypes were determined in 30 and 157 subjects, respectively. AGT M235T genotype, duration of hypertension, body mass index, and ejection fraction statistically affected the left ventricular mass index, which was significantly greater in TT compared to MT carriers after adjusting for confounding factors.

Conclusion: The TT genotype of AGT M23T was associated with greater left ventricular mass in Vietnamese patients diagnosed with essential hypertension.

Association of HLA-B Gene Polymorphisms with Type 2 Diabetes in Pashtun Ethnic Population of Khyber Pakhtunkhwa, Pakistan

Human leukocyte antigen (HLA) system is the most polymorphic and gene dense region of human DNA that has shown many disease associations. It has been further divided into HLA classes I, II, and III. Polymorphism in HLA class II genes has been reported to play an important role in the pathogenesis of type 1 diabetes (T1D). It also showed association with T2D in different ethnic populations. However, a little is known about the relationship of HLA class I gene polymorphism and T2D. This study has evaluated the association of HLA-B (class I gene) variants with T2D in Pashtun ethnic population of Khyber Pakhtunkhwa. In the first phase of the study, whole exome sequencing (WES) of 2 pooled DNA samples was carried out, and DNA pools used were constructed from 100 diabetic cases and 100 control subjects. WES results identified a total of n = 17 SNPs in HLA-B gene. In the next phase, first 5 out of n = 17 reported SNPs were genotyped using MassARRAY® system in order to validate WES results and to confirm association of selected SNPs with T2D. Minor allele frequencies (MAFs) and selected SNPs×T2D association were determined using chi-square test and logistic regression analysis. The frequency of minor C allele was significantly higher in the T2D group as compared to control group (45.0% vs. 13.0%) (p = 0.006) for rs2308655 in HLA-B gene. No significant difference in MAF distribution between cases and controls was observed for rs1051488, rs1131500, rs1050341, and rs1131285 (p > 0.05). Binary logistic regression analyses showed significant results for SNP rs2308655 (OR = 2.233, CI (95%) = 1.223-4.077, and p = 0.009), while no considerable association was observed for the other 4 SNPs. However, when adjusted for these variants, the association of rs2308655 further strengthened significantly (adjusted OR = 7.485, CI (95%) = 2.353-23.812, and p = 0.001), except for rs1131500, which has no additive effect. In conclusion, the finding of this study suggests rs2308655 variant in HLA-B gene as risk variant for T2D susceptibility in Pashtun population.

Recurrent PROC and novel PROS1 mutations in Vietnamese patients diagnosed with idiopathic deep venous thrombosis

INTRODUCTION

Genetic mutations of PROC and PROS1 are well-known risk factors for deep venous thrombosis (DVT) in the Asian population. However, the genetic profile of Vietnamese patients with DVT remains elusive. This study aimed to investigate the spectrum of genetic mutations of these two genes in Vietnamese patients diagnosed with idiopathic DVT.

MATERIALS AND METHODS

A total of 50 Vietnamese patients diagnosed with idiopathic DVT were recruited in this study. The entire coding regions of the protein C and protein S genes were amplified and directly sequenced to determine genetic alterations.

RESULTS

Four and six genetic mutations were detected in protein C and protein S genes, respectively, in 24 Vietnamese DVT patients. PROC c.565C > T (p.R189W) was the most common mutation found in 13 out of 50 patients, while the mutations of PROS1 comprised three missense and three nonsense variants which diffuse along the gene.

CONCLUSIONS

This study shows that mutations of protein C and protein S genes are prevalent in Vietnamese patients diagnosed with idiopathic DVT, and PROC c.565C > T (p.R189W) was the most common genetic alteration.

Risk factors for cutaneous reactions to allopurinol in Kinh Vietnamese: results from a case-control study

OBJECTIVE

The aim of this study was to investigate risk factors for cutaneous adverse reactions (CARs) in Kinh Vietnamese.

METHODS

All patients were prospectively recruited in Ho Chi Minh City. Presence of the HLA-B*58:01 allele was determined by real-time PCR-sequence-specific amplification by using the PG5801 Detection Kit (Pharmigene, Taipei). Patients with severe (SCARs) and mild (MCARs) CARs and controls were compared for differences in features prospectively collected, and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated.

RESULTS

On comparing 32 patients with SCARs and 395 tolerant controls, we identified eight strong risk factors: increased age (OR 15.1 [95% CI 5.8-40.1], P < 0.0001), female sex (OR 333 [40-43,453], P < 0.0001), allopurinol for asymptomatic hyperuricemia (OR 955 [120-125,847], P < 0.0001), allopurinol starting dose > 150 mg (OR 316 [101-122], P < 0.0001), diuretics intake (OR 304 [35-40,018], P < 0.0001), eGFR < 60 ml/min/1.73 m² (OR 100 [32-353], P < 0.0001), history of allopurinol-induced skin reaction (OR 78 [6-10,808], P = 0.004), and HLA-B*58:01 carriage (OR 147 [45-746], P < 0.0001). HLA-B*58:01 allele frequency in controls was 7.3%. For MCARs (n = 74), risk factors were eGFR < 60 ml/min/1.73 m² (OR 4.9 [1.61-14.6], P = 0.006), history of allopurinol-induced skin reaction (OR 27 [2-3777], P = 0.01), and asymptomatic hyperuricemia (OR 27 [2-3777], P = 0.01).

CONCLUSION

This study confirmed 8 risk factors, including HLA-B*58:01, for SCARs and identified 3 risk factors for MCARs in Kinh Vietnamese. HLA-B*58:01 genotyping could guide the indication for allopurinol in Kinh Vietnamese patients with gout.