ABO Gene Research Articles

Novel regulatory variant in ABO intronic RUNX1 binding site inducing A3 phenotype.

Mixed-field agglutination in ABO phenotyping (A3, B3) has been linked to genetically different blood cell populations such as in chimerism, or to rare variants in either ABO exon 7 or regulatory regions. Clarification of such cases is challenging and would greatly benefit from sequencing technologies that allow resolving full-gene haplotypes at high resolution. We used long-read sequencing by Oxford Nanopore Technologies to sequence the entire ABO gene, amplified in two overlapping long-range PCR fragments, in a blood donor presented with A3B phenotype. Confirmation analyses were carried out by Sanger sequencing and included samples from other family members. Our data revealed a novel heterozygous g.10924C>A variant on the ABO*A allele located in the transcription factor binding site for RUNX1 in intron 1 (+5.8 kb site). Inheritance was shown by the results of the donor's mother, who shared the novel variant and the anti-A specific mixed-field agglutination. We discovered a regulatory variant in the 8-bp RUNX1 motif of ABO, which extends current knowledge of three other variants affecting the same motif and also leading to A3 or B3 phenotypes. Overall, long-range PCR combined with nanopore sequencing proved powerful and showed great potential as an emerging strategy for resolving cases with cryptic ABO phenotypes.

ABO Gene is Likely a Genetic Cause of Anxiety Diagnosis

ABO Gene is Likely a Genetic Cause of Anxiety Diagnosis

Identification and Blood Transfusion of a Rare A1.02/BA.02 Genotype.

The aim was to analyze the serological and molecular genetic characteristics of a rare B(A) subtype pedigree, explore its pathogenesis, and discuss transfusion strategies. ABO blood typing serological tests were conducted on a female subject and her family member using standard serological methods. Sequencing analysis of the ABO gene exons 6 and 7 was performed using PCR technique for the female subject and her family member to examine the blood types of the participants. The serological test results showed a discrepancy between the forward and reverse typings of the female subject. The forward typing was similar to that of AB subtype serological forward typing, while the reverse typing indicated AB blood type. Based on the sequencing results, it is inferred that the female subject and her son have 8 mutations on one BA.02 chain: 297A>G, 526C>G, 657C>T, 700C>G, 703G>A, 796C>A, 803G>C, and 930G>A. Comparing these eight mutation sites with the Blood Group Antigen Gene Mutation Database (BGMUT), it was found that the female subject had a heterozygous mutation at c.700C>G in the 7th exon of the B.01 gene, consistent with the characteristics of the BA.02 allele. The genotype of the female subject was determined as A1.02/ BA.02, while the genotype of her son was determined as O.01.01/BA.02. The serological presentation of the B(A) subtype for the female subject reported in this study was unique. It differed from previously reported cases, indicating that the determination of B(A) subtypes cannot solely rely on serological testing. It requires a comprehensive analysis combining the results of genetic testing and pedigree investigation.

In Silico Analysis of Single Nucleotide Polymorphisms Related to Susceptibility and Severity in COVID-19 Patients

Coronavirus disease 2019 (COVID-19) is a respiratory tract symptoms caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which exhibits a wide range of symptoms, from mild to severe. Genetic factors play a significant role in determining severity of the symptoms. Specifically, certain variants within genes can predispose individuals to experience severe COVID-19 symptoms. Therefore, this study aims to analyze these variants, also known as single nucleotide polymorphisms (SNP) within the ABO, TMPRSS2, ACE2, PAI-1, and IFNAR2 genes. The in silico method was used based on internet sites and software to identify the level of SNP pathogenicity, stability, visualization of 3-dimensional protein structures, and figures of amino acid changes as well as to analyze the pathomechanism of variants that lead to susceptibility or severe symptoms of COVID-19 patients. The results showed that the presence of SNP influences changes in the structure or stability of proteins, and the 3-dimensional structure of all proteins affected by SNP was successfully visualized. Based on pathomechanism analysis and amino acid structure of F216I and P74S protein ABO residues, V160M protein TMPRSS2, I468V, and K26R protein ACE2 are associated with susceptibility of the patient to SARS-CoV-2 infection. In addition, the results of the in silico analysis showed that A15T residues of PAI-1 protein, F10V, and F8S IFNAR2 protein were included with pathomechanisms leading to severe symptoms of COVID-19.

The -72G>A nucleotide substitution impairs transcription of the ABO gene via reduction of promoter activity.

The -72G>A nucleotide substitution impairs transcription of the ABO gene via reduction of promoter activity.

Investigation of ABO Gene Variants across More Than 60 Pig Breeds and Populations and Other Suidae Species Using Whole-Genome Sequencing Datasets.

Polymorphisms in the human ABO gene determine the major blood classification system based on the three well-known forms: A; B; and O. In pigs that carry only two main alleles in this gene (A and O), we still need to obtain a more comprehensive distribution of variants, which could also impact its function. In this study, we mined more than 500 whole-genome sequencing datasets to obtain information on the ABO gene in different Suidae species, pig breeds, and populations and provide (i) a comprehensive distribution of the A and O alleles, (ii) evolutionary relationships of ABO gene sequences across Suidae species, and (iii) an exploratory evaluation of the effect of the different ABO gene variants on production traits and blood-related parameters in Italian Large White pigs. We confirmed that allele O is likely under balancing selection, present in all Sus species investigated, without being fixed in any of them. We reported a novel structural variant in perfect linkage disequilibrium with allele O that made it possible to estimate the evolutionary time window of occurrence of this functional allele. We also identified two single nucleotide polymorphisms that were suggestively associated with plasma magnesium levels in pigs. Other studies can also be constructed over our results to further evaluate the effect of this gene on economically relevant traits and basic biological functions.

Rapid ABO genotyping method using loop-mediated isothermal amplification (LAMP) and real-time PCR.

Analyzing all biological evidence at a crime scene presents serious time, budget, and labor constraints. Therefore, selecting valid evidence is crucial for efficient screening. The ABO blood group is a marker that can serve as valid evidence for identifying investigative leads in criminal case. Conventional identification of ABO blood groups using serological methods has only been for blood and is difficult to apply to other body fluids. ABO genotyping was conducted by analyzing single nucleotide polymorphisms (SNP) representative of each blood group. However, this method is time-consuming, expensive, and requires sophisticated instruments. In this study, we developed rapid ABO genotyping method using loop-mediated isothermal amplification (LAMP) and multiplex real-time polymerase chain reaction (PCR). Three SNP sites in the ABO gene (nt 261, 526, and 803) were selected to classify the ABO genotypes. For the specificity test, we performed sequencing of 60 saliva samples to confirm that the genotyping. We conducted experiments to apply ABO genotyping using two amplification methods to mock forensic sample using cotton swab and filter paper. As a result, using LAMP, we successfully identified six ABO genotypes within 30min at a constant temperature (65 ℃). Moreover, by using multiple real-time PCR, it was possible to detect not only the major group but also the subgroup of the ABO genotype (ex. cis-AB). The amplification results using the new methods were in concordance with the sequencing results. Therefore, these ABO genotyping methods are expected to select valid evidence successfully and efficiently at the crime scene.

ABO gene may be salient to the out of Africa migrations to the Americas

The source populations of Native Americans lived in Asia and Eurasia some 35,000 to 40,000 years ago. Consensus is that they migrated to Beringia some 25,000 to 30,000 years ago, when the low sea levels from the Last Glacial Maximum period allowed a land bridge to form to Beringia. Subsequently, the Native American ancestors migrated south to North and South America, whereas the remaining Beringia population, Eskimos, migrated into Canada and Greenland. Genetic evidence along with anthropological research adds much to the understanding of the course of their migrations and population growth. Because present-day Native Americans are essentially all of ABO O blood type, and the other Beringia populations, the Eskimos, were polymorphic for the ABO blood groups given the extensive research revealing pleiotropy of ABO blood group alleles, this unusual population frequency distribution of ABO blood groups offers an opportunity to understand how a population with no diversity of ABO blood groups differs from one that is similar in other genes but polymorphic in ABO blood groups. ABO blood groups in migrating populations provide supporting evidence for the timelines, destinations, and cultures of those populations leaving Africa. Other genes add to the power of ABO blood groups to provide this evidence. One of those genes, in the case of Native American and Eskimo migrations, is the gene for a dental trait called shovel shaped incisors, ectodysplasin A receptor (EDAR), which is prevalent in northeast Asian populations and is fixed in Native American populations. Because of the known climatic conditions in Africa at the time of the major out-of-Africa migration periods and malaria-related climatic aspects of the selection of the ABO A2 vs ABO A1 gene, it appears that the population ratio of ABO A2 to ABO A1 and EDAR associated shovel shaped incisor frequencies is associated with the timelines of the population leaving Africa as well as their further migrations. Because Native Americans have a very high shovel shaped incisor frequency and no ABO A2, their timeline of migrating from northeast Asia and Eurasia, observed using this approach and agreeing with other lines of evidence, is supported to be 25,000–30,000 years ago. Furthermore, separation of the Beringia population into a monomorphic ABO O group, the Native Americans, and an ABO polymorphic group, the Eskimos, in light of research supporting pleiotropy of ABO alleles enhances our understanding of their respective divergent migration paths, cultures, and population growth.

Prevalence and Distribution of ABO and Rh (D) Factor among Blood Donors in the United Arab of Emirates

Abstract Introduction/Objective Karl Landsteiner discovered the ABO blood group system in 1900, which was the first human blood group system. The Rh blood group system was found forty years later. The antigens on the surface of red blood cells are used to classify people into ABO blood groups. In the ABO system, there are four types: A, B, AB, and O; in the rhesus system, there are two types: Rh-positive and Rh-negative. Blood group identification is critical for efficiently managing blood banks and blood transfusion services to avoid serious transfusion reactions. Methods/Case Report The study was performed on a total of 5996 healthy blood donors in the United Arab of Emirates (UAE). ABO and Rh (D) groupings were performed on all donors' samples by the gel electrophoresis technique. Data on the frequency of ABO and Rh(D) blood groups were reported in numbers and percentages. Results (if a Case Study enter NA) The study revealed that type O is the most prevalent blood group in the United Arab Emirates (43.83%), followed by A at 26.68% and B at 23.90%, with AB having the lowest prevalence at 5.58%; O > A > B > AB. Our study found that 92.57% of the donor population was Rh-positive, whereas 7.43% was Rh- negative. The IA, IB, and IO allele frequencies were determined using the Hardy-Weinberg rule of equilibrium. The gene frequencies are calculated to be 0.1942 for IA (p), 0.1438 for IB (q), and 0.6620 for IO (r). O (r) has the most value in UAE, followed by A (p) and B (q); O > A > B. OO constituted 43.83% of the homozygous types, AA 3.77%, and BB 2.06%. The heterozygous types were 25.71% for AO, 19.03% for BO, and 5.58% for AB. Conclusion The study gives reliable ABO gene frequency statistics and information on the distribution of ABO blood group Rh groups of various alleles in the United Arab Emirates. This knowledge aids in the efficient management of the blood bank's inventory. It will aid transfusion services in anticipating future health issues and improving blood transfusion practice. The study is the first to give reliable ABO gene frequency statistics and information on the distribution of ABO blood group Rh groups of various alleles in the United Arab Emirates. This knowledge aids in the efficient management of the blood bank's inventory. It will aid transfusion services in anticipating future health issues and improving blood transfusion practice.

Allele-specific long-range sequencing as a method for ABO haplotyping in clinical blood group diagnosis and immunohematology research.

Safe transfusion therapy requires accurate testing of blood donors and recipients to determine their ABO blood group compatibility. Genotyping does not always clarify serological blood typing discrepancies and conventional PCR methods are not suitable to identify ABO haplotypes. Therefore, an allele-specific long-range sequencing-based typing method was established. Study samples (n = 100) and six patient samples were ABO phenotyped and screened for specific single nucleotide polymorphisms (SNP) in the ABO gene. Based on identified heterozygous SNPs in intron 1 (12897G>A), 2 (437C>T) or 4 (102C>A, 1511G>T) both ABO alleles were investigated separately using a high-fidelity long-range PCR system and Sanger sequencing. The alleles were correlated to the ABO phenotypes determined. Direct sequencing of allelic PCR products up to 6743 bases has been successful in discriminating common combinations of the ABO*A1.01, ABO*A2.01, ABO*B.01, ABO*O.01.01, ABO*O.01.02 and ABO*O.02.01 alleles. 10 out of 64 haplotypes were found to be not previously described. The uncommon ABO*AW.31.01 and the unusual O alleles ABO*O.05 and ABO*O.02.03 alleles were detected in patient samples, resolving the initial inconclusive serologic ABO typing results. This method is an effective tool for analyzing ABO haplotypes. Applicable for ABO molecular diagnostics and immunohematology research it may help to improve pre-transfusion blood type testing.

Detection and phenotype analysis of a novel Ael blood group allele.

The presence of blood subtypes may lead to difficulties in blood group identification; however, third-generation sequencing (TGS) can help in accurately identifying difficult blood groups, and study the serological characteristics and molecular mechanism of Ael subtypes. ABO blood group was identified by the standard serological technique, weak blood group antigen was identified by adsorption-elution experiments, ABH substance in the saliva was determined and glycosyltransferase activity of A and B was detected. The ABO gene full-length sequence and promoter region were amplified by specific primers using single-molecule real-time sequencing, with the amplified products being sequenced directly and analysed in real time. The patient was serologically identified as Ael subtype, and TGS analysis revealed new intron mutations in Ael patients (c.467C>T; c.29-10T>A). The discovery of the new allele and the identification of ABO subtypes can be combined with serological characterization and molecular biological methods.

Biochip with Cells of Brush Polymers Carrying Carboxyl Groups for DNA Analysis

A method for manufacturing biochips by photolithography with hydrogel cells made of brush copolymers based on acrylic acid and acrylamide, fixed at one end on the surface of a polymer substrate has been developed. Hydrogel cells with reactive carboxyl groups were used for covalent immobilization of oligonucleotide probes. The effectiveness of the method was demonstrated in the hybridization analysis of DNA by targets of different lengths of the sequence site 7 of the exon of the human ABO gene.

Molecular analysis and transfusion management in a rare case of cis-AB blood group: A report from India

Molecular characterization of a rare cis-AB blood group has not been done in the Indian subcontinent. Herein, we report a case of A2B3 blood group in an Indian patient which was subsequently confirmed to be a case of cis-AB phenotype. Blood grouping was performed by the column agglutination technique (CAT), conventional tube technique (CTT) and subsequently, whole exome sequencing for molecular analysis. The patient was initially typed as AB, RhD positive in forward grouping. However, serum grouping showed agglutination (2+) with the B red cells in CAT. In CTT, an extra reaction was observed with A1 red cells and a strong agglutination was seen with Anti-H lectin. Thus, the blood group was identified serologically as A2B3. During the next-generation sequencing, a total of 10 exonic variants in the ABO gene were filtered, of which 2 (rs8176747 and rs7853989) were found to be non-synonymous and occurring on the same allele. The other allele was found to be ABO*A1.01. The sample analyzed in the study was found to carry two previously reported nucleotide changes of cis-AB (c.803G > C and c.526C > G) on the same allele which had not been reported before. Transfusion requirement was managed with type O red cells and type AB plasma.

Unraveling Coronary Artery Disease vulnerability in patients with ABO gene polymorphism: A Case-Control Study in Pakistan perspective

Objectives: This study was aimed to explore the association of ABO gene variants with coronary artery disease. Methodology: This was a case-control study. Cases and controls were individuals with greater than 50% and less than 30% stenosis, respectively. One hundred thirty-eight samples were obtained, with 69 cases and 69 controls. The operator completed a proforma regarding demographics, medical history, and blood group. The bench work included blood typing, followed by blood genotyping by DNA extraction, PCR, and then Sanger's sequencing. The single nucleotide polymorphisms (SNPs) selected for the ABO gene were rs8176746 and rs8176719. Results: The results show that 68.1% of the participants were male cases, compared to 49.27% controls. The frequency of patients belonging to the old age group (60-75 years) was 65.21% in cases and 34.78% in controls. A+ was the most prevalent group in cases, with 33.33%, followed by 24.6% B+, 23.2% O+, and 4.3% AB+. Patients with Rh-ve groups were rare. On the contrary, 33.33% of patients were O+ in controls. A chi-square test showed that the A+ blood group was significantly associated with CAD, having a p-value of 0.01. Although blood genotypes did not show a significant p-value, the odds of having genotype AA was 1.35 times higher in cases compared to the controls. Conclusion: This study shows that the A+ group is significantly associated with CAD. The data obtained through Sanger’s sequencing determined the genetic variants of blood groups, but no statistically significant association was found between them and CAD.

Identification of a novel A allele with a nucleotide insert (c.99-1_100 T) in the ABO gene associated with a A3 phenotype individual.

Identification of a novel A allele with a nucleotide insert (c.99-1_100 T) in the ABO gene associated with a A3 phenotype individual.

Identification of a novel variant c.761C>T on ABO*B.01 gene in ABO glycosyltransferases associated with Bweak phenotype.

ABO antigens are produced from H antigen by the activity of glycosyltransferase enzyme encoded by the ABO gene. Variants in the ABO gene can produce a weak ABO phenotype. In this study, we identify a novel ABO*BW allele and investigate the underlying mechanism leading to the Bweak phenotype. The ABO phenotype and genotype of the sample were determined using serological and direct DNA sequencing methods. We assessed the impact of the novel variant by three-dimensional modelling to predict protein stability changes (ΔΔG), and carried out an in vitro expression assay. The total glycosyltransferase transfer capacity in the supernatant of transfected cells was also examined. Serological analysis confirmed the Bweak phenotype in the subject, and gene sequencing identified a novel variant c.761C>T (p.A254V) on the ABO*B.01 allele, resulting in a BW-var/O.01.02 genotype. In silico analysis suggested that the p.A254V variant on the B allele may reduce the stability of glycosyltransferase B (GTB), as indicated by the ΔΔG values. In vitro expression studies showed that the variant p.A254V impaired H to B antigen conversion, although it did not affect the expression of GTB. We identified a novel BW allele and demonstrated that the variant c.761C>T (p.A254V) can cause the Bweak phenotype by reducing the stability of GTB.

Associations of multiple genetic variations with plasma levels of Von Willebrand Factor and clinical phenotype in Iranian patients with Von Willebrand disease type 1

BackgroundGenetic variations influence the Von Willebrand Factor plasma level and function. This study aims to evaluate the frequency and clinical phenotype effects of eight single nucleotide polymorphism candidates in four genes (VWF, STXBP5, CLEC4M, and ABO) in Iranian patients with VWD type 1. MethodThe study recruited 50 patients with VWD type 1 and 100 healthy individuals. The demographic data from all participants were collected, and the High-Resolution Melting technique was used to determine the frequency of specific single nucleotide polymorphisms. Bleeding scores were also obtained from all patients to assess how these genetic variations might affect the severity of their bleeding symptoms. ResultsThe study found notable variations in the occurrence of certain SNPs (rs7853989 and rs8176743 for ABO gene and rs1063856 and rs1063857 for VWF gene) between the control group and the patients. Additionally, the study discovered that two SNPs (rs868875 for CLEC4M gene and rs9390459 for STXBP5 gene) were significantly linked to the severity of bleeding, and two others (rs868875 for CLEC4M gene and rs8176746 for ABO gene) were associated with reduced levels of VWF antigen in the patients. ConclusionAccording to this study, the above-selected SNPs can cause variations in VWF plasma levels in patients with VWD type 1. Furthermore, the effects of SNPs on bleeding phenotype prove the role of these SNPs in the severity of bleeding manifestations in patients.

Contribution of intergenic interactions of polymorphic variants of candidate genes to the development of gastric ulcer

Introduction: Gastric ulcer is a chronic disease with a recurrent course. The morphological substrate during periods of exacerbation are ulcers of the gastric mucosa. Peptic ulcer disease has a high prevalence among the adult population and is often characterized by a complicated course. Hereditary predisposition, along with other external and internal risk factors, plays a role in the etiopathogenesis of the disease. The aim of the study: To evaluate the effect of polymorphic variants of cell adhesion molecule genes on the development of Helicobacter pylori-negative gastric ulcer (GU). Materials and methods: 119 patients with Helicobacter pylori-negative GU and 347 individuals of the control group were examined. The regulatory potential of 7 polymorphic loci of genes of cell adhesion molecules pathogenetically significant for the development of gastric ulcer (rs6136 of the SELP gene, rs8176720, rs2519093, rs507666 of the ABO gene, rs651007, rs579459, rs649129 of the ABO/RF00019 gene) was evaluated using the HaploReg v4.1, PolyPhen-2, GTEx Portal Internet resources. DNA samples isolated from peripheral blood were genotyped by PCR. The analysis of associations was carried out by the method of logistic regression in the framework of allelic, additive, dominant and recessive genetic models. Results: The T allele of the RF00019/ABO gene (rs651007) is a protective factor in the development of H. pylori-negative GU (OR=0.14). This polymorphism is located in the region of histones marking promoters, regions of hypersensitivity to DNAse and the HNF4 regulatory motif, is associated with the expression of the ABO and SURF1 genes and alternative splicing of the ABO and LCN1P1 genes in various organs (tissues), including in the organs of the digestive and nervous systems.

Identification of a novel B allele with a c.145C>T variant.

The authors have disclosed no conflicts of interest. Figure S1: Direct sequence analysis of the partial exon 3 region in the ABO gene of the proband. Direct sequencing revealed the heterozygous sequence (C and T) at nucleotide 145. Figure S2: Direct sequence analysis of the partial exon 3 region in the ABO gene of the proband's father. Direct sequencing revealed the heterozygous sequence (C and T) at nucleotide 145. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

ABO gene polymorphisms are associated with acute coronary syndrome and with plasma concentration of HDL-cholesterol and triglycerides.

The role of ABO gene polymorphisms in acute coronary syndrome (ACS) and lipid metabolism is increasingly recognized. We investigated whetherABO gene polymorphisms are significantly associated with ACS and the plasma lipid profile. SixABOgene polymorphisms (rs651007T/C, rs579459T/C, rs495928T/C, rs8176746T/G, rs8176740A/T, and rs512770T/C) were determined by 5'exonuclease TaqMan assays in 611 patients with ACS and 676 healthy controls. The results demonstrated that the rs8176746Tallele was associated with a lower risk of ACS under the co-dominant, dominant, recessive, over-dominant, and additive models (P= 0.0004,P= 0.0002,P= 0.039, P= 0.0009, andP= 0.0001, respectively). Furthermore, under co-dominant, dominant, and additive models, the rs8176740Aallele was associated with a lower risk of ACS(P= 0.041,P= 0.022, andP= 0.039, respectively). On the other hand, the rs579459Callele was associated with a lower risk of ACS under the dominant, over-dominant, and additive models (P= 0.025,P= 0.035, andP= 0.037, respectively). In a subanalysis performed with the control group, rs8176746Tand rs8176740Aalleles were associated with low systolic blood pressure and with both high high-density lipoprotein-cholesterol (HDL-C) and low triglyceride plasma concentrations, respectively. In conclusion, ABOgene polymorphisms were associated with a lower risk of ACS, and lower systolic blood pressure and plasma lipid levels, suggesting a causal relationship between ABO blood groups and the incidence of ACS.