[Genetic analysis of an individual with A3 phenotype due to variant of A-glycosyltransferase enzyme gene].

OBJECTIVE: To explore the serological characteristics and molecular mechanism underlying an individual with A3 phenotype. METHODS: A 27-year-old ethnic Han Chinese woman presented at the Fourth Affiliated Hospital of China Medical University on May 12, 2022 was selected as the study subject. ABO blood type was determined with standard serological techniques. The ABO gene was subjected to direct sequencing of PCR products. Exons 6 and 7 of the ABO gene were sequenced using specific primers to determine the haplotypes. Bioinformatic software was used to analyze the structure of the mutant protein. RESULTS: Serological typing of the ABO blood group has suggested a rare A3 phenotype. The proband was found to harbor heterozygous c.261delG, c.467C>T and c.745C>T variants by direct sequencing. Single strand sequencing revealed that she has harbored ABO*A3.07 and ABO*O.01.01 alleles. The ABO*A3.07 allele has contained a c.745C>T (p.R249W) variant on the background of an ABO*A1.02 allele. The p.R249W substitution was predicted to be probably damaging by the PolyPhen2 software. The free energy change (ΔΔG) value predicted it to have a destabilizing effect on the GTA protein. Meanwhile, modeling of the 3D structure has predicted that the p.R249W amino acid substitution may alter the hydrogen bond network of the GTA protein. CONCLUSION: The p.R249W substitution of the α-1,3-N-acetylgalactosaminyltransferase gene may reduce the antigen expression owing to a great destabilizing effect on the structure and function of the GTA protein.

[Analysis of a Chinese pedigree with Bw subtype due to a novel variant of α-1,3-N-acetylgalactosaminyltransferase gene].

OBJECTIVE: To explore the serological characteristics and genetic variant in a Chinese pedigree with Bw subtype. METHODS: A 32-year-old female proband who had undergone prenatal examination on December 10, 2020 at the 960th Hospital of the PLA Joint Logistics Support Force and five members from her pedigree were selected as the study subjects. Peripheral blood samples were collected and subjected to ABO blood group phenotyping with serological methods and ABO blood group genotyping with fluorescent PCR. Genetic testing and haplotype analysis were carried out by direct sequencing of the entire coding region of the ABO gene in the proband and cloned sequencing of exons 1-7. RESULTS: The blood type serology of the proband showed Bw, and her ABO blood type genotype determined by fluorescence PCR was B/O. The direct sequencing results showed that the proband had matched the ABO*O.01.01/ABO*B.01 genotype and carried a c.1A>G variant. Cloned sequencing has confirmed the c.1A>G variant to have occurred in the ABO*B.01 allele. Family analysis revealed that the mother of the proband had an O blood type, her husband had a B phenotype, and her three children had a normal B blood type. DNA sequencing showed that the two sons of the proband had a genotype of ABO*B.01 and c.1A>G/ABO*B.01. The daughter of the proband was ABO*O.01.01/ABO*B.01, whilst her mother was ABO*O.01.01/ABO *O.01.02. The novel c.1A>G variant sequence has been registered with the database with a number MZ076785 1. CONCLUSION: The novel c.1A>G variant of exon 1 of α- 1,3 galactose aminotransferase gene probably underlay the reduced expression of B antigen in this pedigree.

Association of blood group O with a recurrent risk for acute lower gastrointestinal bleeding from a multicenter cohort study.

The relationship between blood group and rebleeding in acute lower gastrointestinal bleeding (ALGIB) remains unclear. This study aimed to investigate the association between blood group O and clinical outcomes in patients with ALGIB. The study included 2336 patients with ALGIB whose bleeding source was identified during initial endoscopy (from the CODE BLUE-J Study). The assessed outcomes encompassed rebleeding and other clinical parameters. The rebleeding rates within 30 days in patients with blood group O and those without blood group O were 17.9% and 14.9%, respectively. Similarly, the rates within 1 year were 21.9% for patients with blood group O and 18.2% for those without blood group O. In a multivariate analysis using age, sex, vital signs at presentation, blood test findings, comorbidities, antithrombotic medication, active bleeding, and type of endoscopic treatment as covariates, patients with blood group O exhibited significantly higher risks for rebleeding within 30 days (odds ratio [OR] 1.31; 95% confidence interval [CI] 1.04-1.65; P = 0.024) and 1 year (OR 1.29; 95% CI 1.04-1.61; P = 0.020) compared to those without blood group O. However, the thrombosis and mortality rates did not differ significantly between blood group O and non-O patients. In patients with ALGIB, blood group O has been identified as an independent risk factor for both short- and long-term rebleeding.

Generation of a human iPSC cell line (MUSIi017-A) from a donor with O negative blood type.

The Rh-negative type O blood group (O Rh-) is considered a universal donor for emergency blood transfusions. Due to the constant shortage of this rare blood group, the production of blood cells from iPSCs derived from the O Rh- donor could potentially serve as a limitless blood source for transfusions. In this report, we establish a MUSIi017-A iPSC line from peripheral blood mononuclear cells of a healthy donor with the O Rh- blood group. The established iPSC line exhibited a normal karyotype, showed identical STR compared to donor peripheral blood mononuclear cells, and could differentiate to all three germ layers.

[Distribution Characteristics of Rh Phenotype and Feasibility of Compatible Blood Transfusion in Pregnant and Postpartum Women].

OBJECTIVE: To analyze the distribution characteristics of Rh phenotype in pregnant and postpartum women in Chongqing area, and to explore the clinical significance of Rh phenotype in pregnant and postpartum women and the feasibility of Rh phenotype compatible blood transfusion. METHODS: The ABO blood group and Rh phenotype of 65 161 pregnant and postpartum women were detected by microcolumn gel method, and 48 122 males in the same period were taken as controls. The data were analyzed by Chi-square test. RESULTS: There were 112 870 cases (99.64%) of RhD+ in 113 283 samples. In RhD+ cases, CCDee (48.39%) and CcDEe (32.88%) were the main phenotypes. The first case of D-- phenotype in Chongqing area was detected. 413 cases (0.36%) of RhD- were detected, with ccdee (52.78%) and Ccdee (33.41%) as the main phenotypes. Compared with RhD- group, RhD+ group showed statistically significant difference in Rh phenotype distribution (P < 0.01). Among 65 161 maternal samples, the positive rate of 5 antigens of Rh blood group from high to low was D > e > C > c > E, and there was no significant difference compared with male samples (P >0.05). There was no significant difference in the distribution of Rh phenotype between males and pregnant/postpartum women, as well as between pregnant/postpartum women with different ABO blood groups (P >0.05). In pregnant and postpartum women, there was no significant difference in distribution of Rh phenotype among the normal pregnancy population, the population with adverse pregnancy history, the population using human assisted reproductive technology (ART) and the population with infertility (P >0.05). There was no significant difference in the distribution of Rh phenotype between the 4 populations mentioned above and the inpatients in the local general Grade A hospitals and the blood donors (P >0.05). In RhD positive pregnant and postpartum women, the probability of finding compatible blood for CcDEe phenotype was 100%, the probability of finding compatible blood for CCDee, CcDee and CCDEe phenotypes was 45%-60%, the probability of finding compatible blood for ccDEE, ccDEe and CcDEE phenotypes was 5%-10%, and the probability of finding compatible blood for other phenotypes was lower than 0.5%. The supply of blood with CCDee and ccDEE phenotypes can meet the compatible transfusions requirements of 7 Rh phenotypes in more than 99% of patients. CONCLUSION: Rh phenotype detection should be carried out for pregnant and postpartum women, and it is feasible to carry out Rh phenotype-matched or compatible blood transfusion for pregnant and postpartum women who need blood transfusion.

Associations of air pollution with acute coronary syndromes based on A/B/AB versus O blood types: case-crossover study.

Short-term exposure to air pollutants may contribute to an increased risk of acute coronary syndrome (ACS). This study assessed the role of short-term exposure to fine particulate matter (PM2.5) as well as fine and coarse PM (PM10) air pollution in ACS events and the effect of blood groups on this phenomenon. A retrospectively collected database of 9026 patients was evaluated. The study design was a case-crossover using a conditional logistic regression model. The main analysis focused on PM2.5 levels with a 1 day lag until the ACS event, using threshold-modelled predictor for all patients. Secondary analyses utilized separate threshold-modelled predictors for 2-7-days moving averages and for patients from specific ABO blood groups. Additional analysis was performed with the non-threshold models and for PM10 levels. Short-term exposure to increased PM2.5 and PM10 levels at a 1-day lag was associated with elevated risks of ACS (PM2.5: OR = 1.012 per + 10 µg/m3, 95% CI 1.003, 1.021; PM10: OR = 1.014 per + 10 µg/m3, CI 1.002, 1.025) for all patients. Analysis showed that exposure to PM2.5 was associated with increased risk of ACS at a 1-day lag for the A, B or AB group (OR = 1.012 per + 10 µg/m3, CI 1.001, 1.024), but not O group (OR = 1.011 per + 10 µg/m3, CI 0.994, 1.029). Additional analysis showed positive associations between exposure to PM10 and risk of ACS, with 7-days moving average models stratified by blood group revealing that exposures to PM2.5 and PM10 were associated with elevated risk of ACS for patients with group O. Short-term exposures to PM2.5 and PM10 were associated with elevated risk of ACS. Short-term exposure to PM2.5 was positively associated with the risk of ACS for patients with A, B, or AB blood groups for a 1-day lag, while risk in O group was delayed to 7 days.

Association between plasma proteome and pulmonary heart disease: A two-stage Mendelian randomization analysis.

Pulmonary heart disease (PHD) involves altered structure and function of the right ventricle caused by an abnormal respiratory system that causes pulmonary hypertension. However, the association between changes in plasma proteomics and PHD remains unclear. Hence, we aimed to identify causal associations between genetically predicted plasma protein levels and PHD. Mendelian randomization was performed to test the target proteins associated with PHD. Summary statistics for the human plasma proteome and pulmonary heart disease were acquired from the UK Biobank (6038 cases and 426 977 controls) and the FinnGen study (6753 cases and 302 401 controls). Publicly available pQTLs datasets for human plasma proteins were obtained from a largescale genome-wide association study in the INTERVAL study. The results were validated using a case-control cohort. We first enrolled 3622 plasma proteins with conditionally independent genetic variants; three proteins (histo-blood group ABO system transferase, activating signal cointegration 1 complex subunit 1, and calcium/calmodulin-dependent protein kinase I [CAMK1]) were significantly associated with the risk of pulmonary heart disease in the UK Biobank cohort. Only CAMK1 was successfully replicated (odds ratio: 1.1056, 95% confidence interval: 1.019-1.095, p = 0.0029) in the FinnGen population. In addition, the level of CAMK1 in 40 patients with PHD was significantly higher (p = 0.023) than that in the control group. This work proposes that CAMK1 is associated with PHD, underscoring the importance of the calcium signaling pathway in the pathophysiology to improve therapies for PHD.

Association between blood groups and myocardial injury after non-cardiac surgery: a retrospective cohort study.

Blood group is a potential genetic element in coronary artery disease. Nevertheless, the relationship between different ABO blood groups and myocardial injury after non-cardiac surgery (MINS) is poorly understood. This study verified whether ABO blood group is a potential MINS influencing factor. This retrospective cohort study included 1201 patients who underwent elective non-cardiac surgery and a mandatory troponin test on postoperative days 1 and 2 from 2019 to 2020 at a university-affiliated tertiary hospital. The primary outcome was associations between ABO blood groups and MINS, assessed using univariate and multivariate logistic-regression analyses. Path analysis was used to investigate direct and indirect effects between blood group and MINS. MINS incidence (102/1201, 8.5%) was higher in blood-type B patients than in non-B patients [blood-type B: 44/400 (11.0%) vs. non-B: 58/801 (7.2%); adjusted odds ratio = 1.57 (1.03-2.38); p = 0.036]. In the confounding factor model, preoperative hypertension and coronary artery disease medical history were associated with MINS risk [adjusted odds ratio: 2.00 (1.30-3.06), p = 0.002; 2.81 (1.71-4.61), p < 0.001, respectively]. Path analysis did not uncover any mediating role for hypertension, diabetes, or coronary artery disease between blood type and MINS. Therefore, blood-type B is associated with higher MINS risk; potential mediators of this association need to be investigated.

Gene-Gene Interaction Between Factor-XI and ABO Genes in Cerebral Venous Thrombosis: The BEAST Study.

BACKGROUND AND OBJECTIVES: Gene-gene interactions likely contribute to the etiology of multifactorial diseases such as cerebral venous thrombosis (CVT) and could be one of the main sources of known missing heritability. We explored Factor XI (F11) and ABO gene interactions among patients with CVT. METHODS: Patients with CVT of European ancestry from the large Bio-Repository to Establish the Aetiology of Sinovenous Thrombosis (BEAST) international collaboration were recruited. Codominant modelling was used to determine interactions between genome-wide identified F11 and ABO genes with CVT status. RESULTS: We studied 882 patients with CVT and 1,205 ethnically matched control participants (age: 42 ± 15 vs 43 ± 12 years, p = 0.08: sex: 71% male vs 68% female, p = 0.09, respectively). Individuals heterozygous (AT) for the risk allele (T) at both loci (rs56810541/F11 and rs8176645/ABO) had a 3.9 (95% CI 2.74-5.71, p = 2.75e-13) increase in risk of CVT. Individuals homozygous (TT) for the risk allele at both loci had a 13.9 (95% CI 7.64-26.17, p = 2.0e-15) increase in risk of CVT. The presence of a non-O blood group (A, B, AB) combined with TT/rs56810541/F11 increased CVT risk by OR = 6.8 (95% CI 4.54-10.33, p = 2.00e15), compared with blood group-O combined with AA. DISCUSSION: Interactions between factor XI and ABO genes increase risk of CVT by 4- to 14-fold.

The ABO blood group antigens in patients with oral lichenoid reaction.

Evaluating the association of ABO blood group with different delayed hypersensitivity reactions, such as oral lichenoid reaction (OLR), can provide a new perspective for clinical practice. Therefore, this study designed to investigate ABO blood group antigens in OLR patients. In this case-control study, the ABO blood group of 112 OLR patients and 117 individuals without oral lesions were included. Gender, age, characteristics of the lesions, medications and restorative materials recorded. Chi-square test used to compare the frequency of ABO blood groups in OLR patients with controls. The O blood group was significantly higher in OLR patients and all its subtypes. Also, there were significant relation between O blood group, and severity of lesions. The frequency of dysplasia was non-statistically significant higher in OLR patients with O blood group than other blood group. Based on the results of the present study, O blood group was significantly more in patients with lichenoid reaction than control group, and AB blood group was the lowest. Also, O blood group showed a positive association with the more severe form of OLR lesions and frequency of dysplasia.

Potential therapeutic targets for membranous nephropathy: proteome-wide Mendelian randomization and colocalization analysis.

Background: The currently available medications for treating membranous nephropathy (MN) still have unsatisfactory efficacy in inhibiting disease recurrence, slowing down its progression, and even halting the development of end-stage renal disease. There is still a need to develop novel drugs targeting MN. Methods: We utilized summary statistics of MN from the Kiryluk Lab and obtained plasma protein data from Zheng et al. We performed a Bidirectional Mendelian randomization analysis, HEIDI test, mediation analysis, Bayesian colocalization, phenotype scanning, drug bank analysis, and protein-protein interaction network. Results: The Mendelian randomization analysis uncovered 8 distinct proteins associated with MN after multiple false discovery rate corrections. Proteins related to an increased risk of MN in plasma include ABO [(Histo-Blood Group Abo System Transferase) (WR OR = 1.12, 95%CI:1.05-1.19, FDR=0.09, PPH4 = 0.79)], VWF [(Von Willebrand Factor) (WR OR = 1.41, 95%CI:1.16-1.72, FDR=0.02, PPH4 = 0.81)] and CD209 [(Cd209 Antigen) (WR OR = 1.19, 95%CI:1.07-1.31, FDR=0.09, PPH4 = 0.78)], and proteins that have a protective effect on MN: HRG [(Histidine-Rich Glycoprotein) (WR OR = 0.84, 95%CI:0.76-0.93, FDR=0.02, PPH4 = 0.80)], CD27 [(Cd27 Antigen) (WR OR = 0.78, 95%CI:0.68-0.90, FDR=0.02, PPH4 = 0.80)], LRPPRC [(Leucine-Rich Ppr Motif-Containing Protein, Mitochondrial) (WR OR = 0.79, 95%CI:0.69-0.91, FDR=0.09, PPH4 = 0.80)], TIMP4 [(Metalloproteinase Inhibitor 4) (WR OR = 0.67, 95%CI:0.53-0.84, FDR=0.09, PPH4 = 0.79)] and MAP2K4 [(Dual Specificity Mitogen-Activated Protein Kinase Kinase 4) (WR OR = 0.82, 95%CI:0.72-0.92, FDR=0.09, PPH4 = 0.80)]. ABO, HRG, and TIMP4 successfully passed the HEIDI test. None of these proteins exhibited a reverse causal relationship. Bayesian colocalization analysis provided evidence that all of them share variants with MN. We identified type 1 diabetes, trunk fat, and asthma as having intermediate effects in these pathways. Conclusions: Our comprehensive analysis indicates a causal effect of ABO, CD27, VWF, HRG, CD209, LRPPRC, MAP2K4, and TIMP4 at the genetically determined circulating levels on the risk of MN. These proteins can potentially be a promising therapeutic target for the treatment of MN.

Immuno-Hematologic Complexity of ABO-Incompatible Allogeneic HSC Transplantation.

ABO incompatibility is not considered a contraindication for hematopoietic stem cell transplantation (HSCT). Approximately 30% of transplants from related donors and up to 50% of transplants from unrelated donors are ABO incompatible. Immuno-hematologic investigations allow to estimate donor/recipient ABO mismatch and anti-A/B isohemagglutinin (IHA) titration in the pre-HSCT phase. Immediate hemolysis or delayed complications (passenger lymphocyte syndrome and pure red cell aplasia) can occur post HSCT. Some preventive measures take into consideration either decision-making algorithms based on the recipient's IHA titration or clinical protocols for the removal/reduction of IHAs through plasma exchange or immunoadsorption procedures. Product manipulation through red blood cell (RBC) and/or plasma depletion can also be taken into account. Currently, the best approach in the management of ABO-incompatible transplant is not defined in expert consensus documents or with solid evidence. In addition, the methods for IHA titration are not standardized. A transfusion strategy must consider both the donor's and recipient's blood group systems until the RBC engraftment catches on and ABO conversion (forward and reverse typing) is confirmed on two consecutive and independent samples. Therefore, ABO incompatibility in HSCT represents a demanding immuno-hematologic challenge and requires all necessary preventive measures, including the appropriate selection of ABO blood components for transfusion.

ABO and Rhesus blood groups and multiple health outcomes: an umbrella review of systematic reviews with meta-analyses of observational studies.

BACKGROUND: Numerous studies have been conducted to investigate the relationship between ABO and Rhesus (Rh) blood groups and various health outcomes. However, a comprehensive evaluation of the robustness of these associations is still lacking. METHODS: We searched PubMed, Web of Science, Embase, Scopus, Cochrane, and several regional databases from their inception until Feb 16, 2024, with the aim of identifying systematic reviews with meta-analyses of observational studies exploring associations between ABO and Rh blood groups and diverse health outcomes. For each association, we calculated the summary effect sizes, corresponding 95% confidence intervals, 95% prediction interval, heterogeneity, small-study effect, and evaluation of excess significance bias. The evidence was evaluated on a grading scale that ranged from convincing (Class I) to weak (Class IV). We assessed the certainty of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation criteria (GRADE). We also evaluated the methodological quality of included studies using the A Measurement Tool to Assess Systematic Reviews (AMSTAR). AMSTAR contains 11 items, which were scored as high (8-11), moderate (4-7), and low (0-3) quality. We have gotten the registration for protocol on the PROSPERO database (CRD42023409547). RESULTS: The current umbrella review included 51 systematic reviews with meta-analysis articles with 270 associations. We re-calculated each association and found only one convincing evidence (Class I) for an association between blood group B and type 2 diabetes mellitus risk compared with the non-B blood group. It had a summary odds ratio of 1.28 (95% confidence interval: 1.17, 1.40), was supported by 6870 cases with small heterogeneity (I2 = 13%) and 95% prediction intervals excluding the null value, and without hints of small-study effects (P for Egger's test > 0.10, but the largest study effect was not more conservative than the summary effect size) or excess of significance (P < 0.10, but the value of observed less than expected). And the article was demonstrated with high methodological quality using AMSTAR (score = 9). According to AMSTAR, 18, 32, and 11 studies were categorized as high, moderate, and low quality, respectively. Nine statistically significant associations reached moderate quality based on GRADE. CONCLUSIONS: Our findings suggest a potential relationship between ABO and Rh blood groups and adverse health outcomes. Particularly the association between blood group B and type 2 diabetes mellitus risk.

Neonatal screening of ABO/RhD blood group and direct antiglobulin Coombs test. Experience of a single institution.

BACKGROUND: Evaluating the ABO/RhD blood group and the direct antiglobulin Coombs test (DAT) at birth is recommended good practice, but there is variability in its universal implementation. This study aims to show the comparative results in various variables of clinical impact during the hospital stay of neonates with positive DAT compared with those with negative DAT, based on the systematic detection of the ABO/RhD group and DAT at birth. METHODS: Newborns between 2017 and 2020 in a high-risk pregnancy care hospital were included. The ABO/RhD and DAT group was determined in umbilical cord samples or the first 24 hours of life. Demographic, maternal, and neonatal variables were recorded. The association between the variables was estimated using the odds ratio (OR). RESULTS: 8721 pairs were included. The DAT was positive in 239 newborns (2.7%), with the variables associated with positive PDC being maternal age > 40 years (OR: 1.5; 95% CI: 1.0 to 2.3), birth by cesarean section (1.4; 1.1-2.0), mother group O (6.4; 3.8-11.8), prematurity (3.6; 2.6-5.0), birth weight < 2500 g (2.1; 1.6-2.8), newborn group A (15.7; 10.7-23.1) and group B (17.6; 11.4-27.2), hemoglobin at birth < 13.5 g/dl (4.5; 2.8-7.1) and reticulocytosis > 9% (1.9; 1.2 to 3.1). DISCUSSION: The frequency of neonatal positive PDC was 2.7%, with a significant association with maternal/neonatal incompatibility to the ABO and RhD group, with a substantial impact on various neonatal variables. These results support the policy of universal implementation at the birth of the ABO/RhD and DAT determination.

INTRODUCCIÓN: La determinación del grupo sanguíneo ABO/RhD y la prueba directa de Coombs (PDC) al nacimiento son una práctica recomendada, pero existe variabilidad en su implementación universal. Se presentan los resultados de la determinación al nacimiento del grupo ABO/RhD y la PDC en una cohorte institucional. MÉTODOS: Se incluyeron los recién nacidos entre 2017 y 2020 en un hospital de atención a embarazos de alto riesgo. Se determinó el grupo ABO/RhD y se realizó la PDC en muestras de cordón umbilical o en las primeras 24 horas de vida. Se registraron las variables demográficas, maternas y neonatales. Se estimó la asociación entre las variables mediante la razón de probabilidad (OR). RESULTADOS: Se incluyeron 8721 binomios. La PDC fue positiva en 239 recién nacidos (2.7%), siendo las variables asociadas a la PDC positiva la edad materna > 40 años (OR: 1.5;IC95%: 1.0-2.3), el nacimiento por vía cesárea (1.4; 1.1-2.0), la madre del grupo O (6.4; 3.8-11.8), la prematuridad (3.6; 2.6-5.0); el peso al nacer < 2500 g (2.1; 1.6-2.8); el neonato del grupo A (15.7; 10.7-23.1) o del grupo B (17.6; 11.4-27.2), la hemoglobina al nacer < 13.5 g/dl (4.5; 2.8-7.1) y la reticulocitosis > 9% (1.9; 1.2 a 3.1). DISCUSIÓN: La frecuencia de PDC positiva neonatal es del 2.7%, con asociación significativa la incompatibilidad materna/neonatal al grupo ABO y RhD, con impacto significativo en diversas variables neonatales. Estos resultados apoyan la política de implementación universal al nacimiento de la determinación de ABO/RhD y PDC.

[Genetic analysis of two patients with a rare Ael subtype].

OBJECTIVE: To analyze the genetic sequences of two patients with a rare Ael blood subgroup. METHODS: Two female patients undergoing treatment respectively for adenomyoma of the uterus and gastritis at the Second Affiliated Hospital, Yuying Children's Hospital of Wenzhou Medical University in June 2019 and September 2020 were selected as the study subjects. Their Ael subtypes were identified with a saline tube agglutination assay and absorption-emission assay. Sequence of the ABO gene Ael subtypes was determined by the Sanger method. The impact of genetic variants on the structural stability of N-acetylgalactosaminyl transferase (GTA) was analyzed with PyMOL software by constructing a structure predicted model. RESULTS: Both patients were determined as Ael blood subgroup. Sequencing result of patient 1 was ABO*O.01.02/ABO*O.01.02, which has resulted in a p.Thr88Profs*31 amino acid substitution. The sequencing result of patient 2 was ABO*Ael.06/ABO*O.01.02, in which c.425C>T and c.467C>T variants in exon 7 have led to p.Met142Thr and p.Pro156Leu substitutions. Prediction of the protein model speculated that the p.Met142Thr not only can change the binding of GTA protein with water molecules, but also the local hydrogen bond network of GTA, which may lead to decreased enzymatic activity. By contrast, the p.Pro156Leu variant has trivial effect on the structural stability of GTA. CONCLUSION: The molecular structure of Ael subtypes can be diverse. The genotypes of the two patients have been respectively determined as ABO*O.01.02/ABO*O.01.02 with a G261 deletion and ABO*Ael.06/ABO*O.01.02.

[Molecular study of an individual with Bel subtype due to a novel c.620T>C variant].

OBJECTIVE: To explore the molecular basis for an individual with Bel subtype of the ABO blood type due to a novel c.620T>C variant gene, and assess its impact on the structure of GTB transferase. METHODS: An individual who had visited the First Affiliated Hospital of Zhengzhou University on February 11, 2023 was selected as the study subject. ABO phenotyping was initially conducted with serological methods, which was followed by direct sequencing of 7 exons of the ABO gene. Subsequently, single-strand sequencing was carried out by using allele-specific primers, and the variant in the B transferase was homology-modeled using the Modeller software. The impact of the variant on the transferase's spatial structure was analyzed with the PyMOL software. RESULTS: The serological phenotype of the patient was identified as the Bel subtype. Direct sequencing revealed that she has harbored a novel c.620T>C variant, resulting in a p.Leu207Pro substitution in the polypeptide chain. Combined with single-strand sequencing, her genotype was ultimately determined as ABO*BELnew/ABO*O.01.02. Three-dimensional protein structure modeling showed that, compared with the wild type, the distance of one hydrogen bond between Proline and Glycine at position 272 has increased, along with disappearance of another hydrogen bond. CONCLUSION: The novel c.620T>C (p.Leu207Pro) variant of B allele may affect the structural stability of the glycosyltransferase. The weakened enzyme activity in turn may lead to reduced B antigen expression, manifesting as the Bel subtype by serological analysis.

Blood Phytosterol Concentration and Genetic Variant Associations in a Sample Population.

The main objective of this study was to determine plasma levels of PS and to study SNVs rs41360247, rs4245791, rs4148217, and rs11887534 of ABCG8 and the r657152 SNV at the ABO blood group locus in a sample of a population treated at our hospital, and to determine whether these SNVs are related to plasma PS concentrations. The secondary objective was to establish the variables associated with plasma PS concentrations in adults. Participants completed a dietary habit questionnaire and a blood sample was collected to obtain the following variables: campesterol, sitosterol, sitostanol, lanosterol, stigmasterol, biochemical parameters, and the SNVs. In addition, biometric and demographic variables were also recorded. In the generalized linear model, cholesterol and age were positively associated with total PS levels, while BMI was negatively related. For rs4245791, homozygous T allele individuals showed a significantly lower campesterol concentration compared with C homozygotes, and the GG alleles of rs657152 had the lowest levels of campesterol compared with the other alleles of the SNV. Conclusions: The screening of certain SNVs could help prevent the increase in plasma PS and maybe PNALD in some patients. However, further studies on the determinants of plasma phytosterol concentrations are needed.