OBJECTIVE: To explore the serological and molecular genetic characteristics of a family with subtype B(A)06. METHODS: A neonatal hyperbilirubinemia patient who was treated at Henan Children's Hospital on June 15, 2023 due to "yellowing of the skin and gradual aggravation", and was found to have inconsistent ABO forward and reverse typing through blood type testing, was selected as the research subject. Six milliliters of peripheral blood were collected from the newborn and her family members (grandfather, grandmother, father, mother and aunt) respectively. ABO blood group identification was performed by the blood group serological method. Human genomic DNA was extracted using the nucleic acid extraction or purification reagent BT-01. ABO gene exons 2 to 7 were amplified by PCR. The PCR-specific products that were successfully amplified were sequenced by Sanger method. Taking ABO*A1.01 as the reference sequence, the ABO gene sequences of the newborn and her family members were analyzed to determine the ABO genotype. The procedures followed in this study were approved by the Ethics Committee of Henan Children's Hospital (Ethics No.: 2022-K-L036). RESULTS: The serological results of ABO blood group showed that the newborn, her grandfather, father and aunt were all incompatible with the forward and reverse typing. The blood group phenotype of the newborn was AwB or B(A), the blood group phenotype of the grandfather was A2B or B(A), the blood group phenotype of the father and aunt were A2B, and the blood group phenotype of the grandmother and mother were both O. The screening test results of hemolytic disease of the newborn showed that the free test detected IgG anti-A1 antibody, while the elution test, direct antiglobulin test and antibody screening results were all negative. The Sanger sequencing results showed that the newborn had variations of c.261delG, c.297A>G, c.526C>G, c.657C>T, c.703G>A, c.796C>A and c.930G>A. Her grandfather had variations of c.297A>G, C.526C>G, c.657C>T, c.703G>A, c.796C>A, c.803G>C and c.930G>A. Her grandmother had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.646T>A, c.681G>A, c.771C>T and c.829G>A. Her father and aunt had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.526C>G, c.646T>A, c.657C>T, c.681G>A, c.703G>A, c.771C>T, c.796C>A, c.829G>A and c.930G>A. Her mother had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.646T>A, c.681G>A, c.771C>T, and c.829G>A.The genotype of the newborn was ABO*BA.06/ABO*O.01.01, her grandfather was ABO*BA.06/ABO*B.01, her grandmother was ABO*O.01.02/ABO*O.01.02, her father and aunt were ABO*BA.06/ABO*O.01.02, and her mother was ABO*O.01.01/ABO*O.01.02. The ABO*BA.06 allele of the newborn, grandfather, father and aunt was caused by the c.803C>G variation in exon 7 based on the ABO*B.01 allele. The ABO*BA.06 allele can be stably inherited in this family. CONCLUSION The blood type of neonatal patients with B(A)06 subtype can be accurately determined by gene sequencing technology. If the forward typing is ≤ 3+ agglutination intensity in newborn ABO blood group identification, the reason should be carefully analyzed, and the molecular biology technology and family gene sequencing results should be used to jointly determine if necessary.
Humans ; ABO Blood-Group System/genetics* ; Female ; Pedigree ; Male ; Infant, Newborn ; Asian People/genetics* ; Genotype ; China ; Blood Grouping and Crossmatching ; Hyperbilirubinemia, Neonatal/blood* ; East Asian People

OBJECTIVE: To explore the serological characteristics and bioinformatics analysis results of 4 blood donors with RHCE*cE(281C, 282T) variant allele. METHODS: A total of 4 non-related blood donors with RHCE*cE (281C, 282T) variant allele (donors 1-4) were selected as the study objects. They donated blood at Shenzhen Blood Center from January 2022 to June 2023. The 4 blood donors were all Han. And 5 mL elbow venous blood was collected from these 4 blood donors. Regular serological assaying with 4 kinds of monoclonal antibody reagents was used for determination of the RhCcEe type. The nucleotide sequences of all 10 exons and adjacent flanking intron regions of RHCE gene in these 4 donors were analyzed by Sanger sequencing, and the full-length haplotype analysis of RHCE gene was performed by using the single-molecule real-time sequencing (SMRT) third-generation technology. DeepTMHMM software was used to analyze the structure of protein transmembrane region of wild type and variant RhCcEe protein and predict the location of amino acid substitution. The effects of mutations on RhCcEe protein function were analyzed using PolyPhen-2, SIFT and Mutation Taster bioinformatics software. Robetta and Swiss-PdbViewer v4.1.0 were used for modeling the tertiary structures of RhCcEe to analyze the difference between wild type and variant RhCcEe protein. The mutation was rated according to the standards and guidelines for the classification of genetic variants of the American College of Medical Genetics and Genomics (ACMG). This study has been approved by the Medical Ethics Committee of Shenzhen Blood Center (Approval No. SZBCMEC-2022-024). RESULTS: The RhCcEe phenotypes of the 4 blood donors were CCEweake by serological assaying. The RhE antigen were weakly expressed form 0 to 3+. The analysis of RHCE gene sequence indicated that all the 4 donors with RHCE*cE (281C, 282T) allele. The mutation caused the substitution of a single amino acid in the RhCcEe protein (p.Leu94 Pro) and the amino acid substitution was located in the transmembrane α3 chain resulted in significant changes in the 3D structure of the extracellular region of RhCcEe protein. The substitution was predicted to be "Probably damaging", "Damaging" and "Polymorphism" by PolyPhen-2, SIFT and Mutation Taster bioinformatics software. According to the guidelines of ACMG, the variant was rated to be likely pathogenic. CONCLUSION The RHCE*cE (281C, 282T) variant allele was first found in the Han Chinese population. The serological data of this allele were enriched. It provides an important guarantee for the safety of blood transfusion. Bioinformatics analysis provided evidences for further study of the structure and functions of RhCcEe protein.
Humans ; Blood Donors ; Computational Biology/methods* ; Alleles ; Rh-Hr Blood-Group System/genetics* ; Male ; Female ; Adult ; Exons

OBJECTIVE: To report the blood group antigen and antibody specificity identification methods for a patient with high-frequency antibodies, and the process of finding and providing compatible blood for the patient. METHODS: A patient sent from the Blood Transfusion Department of Shanxi Provincial People's Hospital to Blood Transfusion Technology Research Laboratory of Taiyuan Blood Center in November 2022 was selected for the study. Classical serological methods were used to determine the patient's blood type, screen for unexpected antibodies, identify antibodies, and perform crossmatching. High-frequency antibody identification was carried out using red blood cells treated with various enzymes. Blood group genotyping was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) and Sanger sequencing. Multiple strategies were employed to address the patient's blood source problem. The study was approved by the Medical Ethics Committee of Taiyuan Blood Center [Ethics No. 2024 Ethics Review No.(2)]. RESULTS: The patient's blood type was B, RhD positive. Initial screening of the patient's serum with multiple screening cells and antibody identification cells in saline medium was negative, but positive in antiglobulin medium. The patient's serum showed varying reaction intensities with red blood cells treated with different enzymes. MALDI-TOF mass spectrometry and Sanger sequencing revealed a homozygous nonsense variant c.376C>T (p.Gln126Ter) in the ABCG2 gene, resulting in the Jr(a-) phenotype. During family donor selection, the patient's son was found to have a heterozygous variant c.376C>T (p.Gln126Ter), and another heterozygous variant c.421C>A (p.Gln141Lys), which predicted a Jr(a+w) phenotype. Crossmatch tests confirmed the compatibility of blood from the patient's son, which was used to address the urgent blood requirement. Later, rare blood from a Jr(a-) donor from the Guangzhou Blood Center was used for the patient's ongoing treatment, saving the patient's life. CONCLUSION Combining classic serological testing with blood group gene typing techniques successfully identified the rare Jr(a-) blood type and high-frequency anti-Jra antibodies. Enzyme-treated red blood cell identification methods confirmed the presence of anti-Jra antibodies. By searching within the family and seeking help from other blood centers, compatible blood was found. This approach may provide insights for resolving similar complex blood matching problems in the future.
Humans ; Blood Grouping and Crossmatching/methods* ; Blood Group Antigens/immunology* ; Blood Transfusion ; Male ; Isoantibodies/blood* ; Female ; Genotype

OBJECTIVE: To analyze the diversity of Duffy blood group gene among ethnic Hui population from Henan Province using PacBio long-read sequencing technique. METHODS: Randomly select 30 individuals with three generations of Hui ancestry from Henan as the study subjects. Full-length sequences of the Duffy blood group gene were obtained through PacBio long-read sequencing. Distribution of the predicted phenotype and genotype frequency were determined, and the linkage between Duffy haplotypes and variation sites was analyzed. Genetic diversity, natural selection pressure, and population genetic characteristics were evaluated. This study was approved by the Second Affiliated Hospital of Zhengzhou University (Ethics No. 2022223). RESULTS: The predicted Duffy blood group phenotype in the Henan Hui population was predominantly Fy(a+b-). Three novel SNPs in the FY*01 allele were identified, with a total frequency of 13.33%, among which FY*01.NEW1 (c.199C>T) was the most common. A total of 32 variant sites were identified, with 28 located in intronic regions, indicating that genetic diversity was primarily concentrated in introns. The Duffy blood group gene was under negative selection pressure (dN/dS < 1, Tajima's D, Fu and Li's D* and F* significantly deviated from 0), suggesting overall conservation. The allele frequencies of Duffy blood group in the Henan Hui population was similar to that of the Xinjiang Hui, Xinjiang Kazakh, Inner Mongolia Mongolian, and Yuncheng Han populations, but significantly different from those of most Han and other ethnic groups (P < 0.05). CONCLUSION This study revealed the characteristics of the Duffy blood group gene among the Henan Hui population and demonstrated the significant advantages of PacBio long-read sequencing technique in haplotype analysis, genetic diversity study, and novel mutation identification.
Female ; Humans ; Male ; Asian People/ethnology* ; China/ethnology* ; Duffy Blood-Group System/genetics* ; Ethnicity/genetics* ; Gene Frequency ; Genetic Variation ; Haplotypes ; Polymorphism, Single Nucleotide

OBJECTIVE: To investigate a case of antibodies against high-frequency erythrocyte antigens and elucidate the genetic mechanism underlying the blood group. METHODS: A Lan-negative patient referred to the Zhejiang Blood Center by Quzhou Hospital of Traditional Chinese Medicine in August 2016 was selected as the study subject. A retrospective study was conducted to collect the proband's clinical data. The proband's erythrocyte antigens and unexpected serum antibodies were identified using tube saline and microcolumn agglutination anti-human globulin methods. Antibody specificity was determined by treating erythrocytes with 7 enzymes and 2 chemical reducing agents. Genomic DNA was extracted from the proband's blood sample for whole genome sequencing (WGS) and erythrocyte blood group gene analysis, with validation by Sanger sequencing. Multiple bioinformatics tools were used to analyze the pathogenicity of the variant. The rare blood group and unexpected antibody specificity were comprehensively determined based on the results of serological and genetic testing. This study has been approved by the Zhejiang Provincial Blood Center Medical Ethics Committee(Ethics No.20190201). RESULTS: The proband was a 91-year-old Han Chinese male with prostatitis, cystitis, and malnutrition in conjunct with emaciation. He had a history of multiple erythrocyte transfusions without observable adverse reactions. Prior to the most recent transfusion, major crossmatch agglutination was observed, which prompted antibody identification. Antibodies against high-frequency antigens were detected in the proband's serum, with enzyme and reducing agent treatments ruling out antibody specificities associated with 17 blood group systems, e.g., MNS, LU, KEL. WGS analysis identified 4 525 SNPs and 1 046 INDEL variants among erythrocyte blood group genes. Further screening revealed that the proband had a rare blood group due to a homozygous rs755723161 variant. This variant in the ABCB6 gene (c.459delC) has led to a frameshifting mutation (p.Trp154GlyfsTer96), resulting in the Lan-negative rare blood group with a high-frequency antigen deficiency and the production of IgG anti-Lan antibodies in the serum. CONCLUSION This study has identified anti-Lan alloantibodies in a Lan-negative patient and, for the first time, elucidated the ABCB6 gene variant underlying the Lan-negative rare blood group in the Chinese population.
Humans ; Male ; Blood Group Antigens/immunology* ; Aged, 80 and over ; Retrospective Studies ; ATP-Binding Cassette Transporters

OBJECTIVE: To carry out serological and molecular tests on 12 blood donors and family members of one proband with discrepancy results for ABO serological typing. METHODS: Twelve blood donors with ABO discrepancies identified by the Blood Center of Shaanxi Province from March 2015 to December 2023 and family members of one proband were selected as the study subjects. Serological blood typing was carried out to determine their blood phenotype. ABO genotype of the samples was determined by direct sequencing of amplicons of exons 1 to 7 and cloning sequencing of amplicons of exons 6 and 7. This study has been approved by the Ethics Committee of Blood Center of Shaanxi Province (202328). RESULTS: Serological results showed that 5 samples were Aweak, 4 samples were Aweak with anti-A1 antibody, and 3 samples were AweakB with anti-A1. Direct sequencing and cloning sequencing results showed that all 12 samples had the haplotype ABO*A1.01/c.389T>C, and family studies showed that the allele could be stably inherited. Glycosyltransferase activity in the plasma was decreased in all samples. CONCLUSION The c.389T>C variant of the ABO*A1.01 allele can alter the encoded amino acid p.Leu130Pro, which weakens the activity of A glycosyltransferase, ultimately leading to the weak expression of A antigen.
Humans ; ABO Blood-Group System/genetics* ; Blood Donors ; Alleles ; Male ; Female ; Exons ; Genotype ; China ; Adult ; Base Sequence ; Haplotypes

OBJECTIVE: To explore the regulatory mechanisms underlying the weak expression of ABO blood group antigens due to variants in the non-coding regions of the ABO gene. METHODS: From June 2014 to October 2023, a total of 29 samples from the Taiyuan Blood Center and local hospitals, which were serologically identified as having weak ABO antigen expression without detectable coding region mutations, were selected for this study. Full-length ABO gene sequencing was performed using third-generation long-read sequencing technology (Pacific Biosciences) to obtain complete haplotype sequences of the ABO gene. Variants in the non-coding regions were compared and identified to infer their regulatory effects on weak antigen expression. The procedures followed in this study were in accordance with the ethical standards of the World Medical Association's Declaration of Helsinki (2013 revision). The Medical Ethics Committee of Taiyuan Blood Center has granted an exemption from ethical review. RESULTS: 18 bp deletions in the -35 to -18 region of the promoter were identified in 7 samples. Variants in intron 1 (+5.8 kb) were detected in 7 samples, including ABO*A (28+5792_5793delCT (1 case) and ABO*B (28+5793T>C) located in the GATA binding region; ABO*B (28+5808C>T) (1 case) in the E-box region; and ABO*B (28+5875C>T) (4 cases) in the RUNX1 binding region. Nucleotide variants at splice sites were detected in 2 samples, namely ABO*B (C.98+1G>A) and ABO*B (C.204-2A>C). CONCLUSION Variants in the non-coding regulatory sequences of the ABO gene are a significant factor contributing to weak ABO antigen expression. In clinical ABO sequencing, it is essential to screen not only the conventional coding regions but also the flanking sequences, introns, and splice sites of the ABO gene to facilitate precise blood transfusion.
ABO Blood-Group System/genetics* ; Humans ; Alleles ; Promoter Regions, Genetic ; Haplotypes ; Introns

OBJECTIVE: To analyze the sequencing results, protein structure model, and impact of mutations on the dynamic stability of glycosyltransferase (GTA) in a case with Aw26 blood group subtype. METHODS: ABO phenotype was determined by serological testing (anti-A, anti-B, anti-H, and reverse typing). Potential variant of the ABO gene was identified by Sanger sequencing, and the haploid sequence of the variant site was analyzed by TOPOT-A cloning. Molecular models of the GTA was generated by PyMol, and 100-ns molecular dynamics (MD) was simulated with GROMACS software to assess the conformational stability using root mean square deviation (RMSD), radius of gyration (Rg), solvent-accessible surface area (SASA), hydrogen bonding, and binding free energy. RESULTS: Serological assays confirmed the proband as an Aw subtype, whose genotype was identified as ABO*Aw.26/ABO*O.01.02 with variants including p.Pro156Leu, p.Arg176His and p.Pro354ArgfsTer23. Haploid sequencing validated the results of direct sequencing. Molecular modeling showed that the p.Arg176His variant could reduce water-mediated hydrogen bonds from six (wild-type) to one (variant). MD simulation revealed the wild type system could achieve equilibrium within 10 ns (mean RMSD ≈ 0.30 nm), whilst the mutant system required 50 ns to equilibrate and exhibited greater fluctuation (mean RMSD ≈ 0.40 nm). Root mean square fluctuation (RMSF) analysis confirmed significantly increased flexibility in the mutant's N-terminal loop (residues 63-76). The mutant Rg displayed an expansion-contraction transition within 0 ~ 40 ns, and its SASA value has increased. The number of hydrogen bonds and binding energy of the mutant had decreased (wild-type: 5 to 8, binding energy: -11.53 kcal/mol; mutant: 2 to 5, binding energy:-8.52 kcal/mol). CONCLUSION An Aw26 subtype was identified. The p.Arg176His and p.Pro354Argfs*23p variants could synergistically compromise the structural stability of GTA and its substrate binding capacity by disrupting the hydrogen-bond network, increasing local flexibility, and reducing the overall conformational stability.
ABO Blood-Group System/chemistry* ; Humans ; Molecular Dynamics Simulation ; Models, Molecular ; Mutation ; Genotype ; Protein Conformation ; Glycosyltransferases/chemistry* ; Male

OBJECTIVE: To explore the molecular mechanism of a case with RhD-- phenotype. METHODS: A proband with RhD-- phenotype who attended the clinic of the First Affiliated Hospital of Zhengzhou University on January 29, 2024 was selected as the study subject. Peripheral blood samples were collected from the proband (8 mL) and her close relatives (father, mother and brother; 3 mL each) for Rh phenotyping and irregular antibodies testing with gel card and test tube methods. Direct agglutination reaction and absorption-elution test were used to detect the c antigen on the red blood cells of the proband. PCR-sequence specific primers (PCR-SSP) typing and gene sequencing were used to determine the RHCE gene of the proband and her relatives. The origin of the proband's variant was traced by pedigree analysis. Three-dimensional structural models of the wild-type RhCE*cE protein and the RhD-- phenotype protein were constructed to predict the alterations of the RhD-- phenotype protein caused by the variant. The procedures of this study were approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No.: 2023-KY-0870-003). RESULTS: The red blood cells of the proband did not agglutinate with anti-C, anti-c, anti-E, and anti-e. The result of the serum irregular antibody test was negative. The results of direct agglutination reaction and absorption-elution test of the proband were both negative. Her Rh blood group was identified as RhD--. The results of the Rh blood grouping of her close relatives were normal. PCR-SSP detection showed that the RHCE genotypes of the proband and her close relatives were cE/cE and Ce/cE, respectively. Gene sequencing analysis showed that the RHCE genotypes of the proband and her close relatives were RHCE*cE (c.365C>A)/RHCE*cE (c.365C>A) and RHCE*Ce/RHCE*cE (c.365C>A), respectively. Pedigree analysis revealed that the variants in the proband were inherited from her father and mother, respectively. Homology modeling of RhCE*cE protein showed that the RhD-- type peptide chain with a significantly shortened C-terminal was encoded by only 121 amino acid resides, which was 296 amino acid resides shorter compared to the wild-type RhCE*cE peptide chain encoded by 417 amino acid residues. CONCLUSION Above results revealed the molecular biological mechanism of a RhD-- phenotype. The c.365C>A variant in the RHCE gene has rendered the RHCE*cE alleles invalid, which ultimately led to the RhD-- phenotype.
Humans ; Rh-Hr Blood-Group System/chemistry* ; Female ; Phenotype ; Male ; Alleles ; Pedigree ; Base Sequence ; Molecular Sequence Data ; Adult

OBJECTIVE: To analyze the ABO serological and molecular characteristics of a Chinese pedigree carrying an ABO*cisAB.01 allele for the blood subgroup. METHODS: A proband undergoing blood preparation for a surgery due to an open rupture of the extensor hallucis longus tendon in the left thumb on September 5, 2024 at Weihai Central Hospital and his family members were selected as study subjects. ABO serological type of six individuals from three generations was determined by serological methods. PCR was carried out to amplify exons 6 and 7 of the ABO gene, and the amplified products were directly sequenced. Samples of the proband and his mother, son, and daughter were subjected to clone sequencing analysis. This study was approved by the Medical Ethics Committee of Weihai Central Hospital (Ethics No.: LL-2024-269-01). RESULTS: Serological testing showed that the proband and his mother were of the AB subtype, whilst his daughter was A subtype B, his father was of O, his wife was AB, and his son was A. Direct sequencing showed that the proband's genotype was ABO*cisAB.01/O.01.02, and his mother, son, and daughter had all carried an ABO*cisAB.01 allele. There were significant differences in allelic competition when the A, B and O genes were co-dominant with the cisAB.01 allele, respectively. CONCLUSION There is allelic competition between the cisAB.01 allele and different ABO alleles. Blood type serological tests combined with molecular methods and family investigations can help ascertain and interpret the ABO blood type phenotypes.
Humans ; ABO Blood-Group System/genetics* ; Male ; Female ; Phenotype ; Pedigree ; Alleles ; Genotype ; Adult ; Asian People/genetics*