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 Medical Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (Ethics No. 202223).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*& 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.

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.

Objective: To reveal the molecular basis of the cisAB (p. Met266Leu) glycosyltransferase by studying a proband with cisAB subtype and his family. Methods: A male newborn was selected as the research subject. Tube methods were used to identify ABO blood types of the proband and his family members. PCR-SSP detection, ABO gene sequencing, and cloning analysis were performed on the proband and some family members. The inheritance pattern of the subtype gene in the family was determined through pedigree analysis. Homology modeling was used to analyze the impact of amino acid variations on the structure of the transferase, and molecular docking was used to demonstrate the bifunctional activity of the transferase and the donor-receptor binding conformation. Results: Serological tests showed that the proband and his father had enhanced anti-H agglutination, and the grandmother had a forward and reverse discrepancy. Sequencing of the proband revealed heterozygous variations of c. 297A>G, c. 526C>G, c. 657C>T, c. 703G>A, c. 803G>C, and c. 930G>A compared with A1. 01 (compared with B. 01, lacking the c. 796C>A variation, namely harboring the c. 796A>C variation) and c. 261delG. Combined with cloning analysis, the proband's genotype was determined to be ABO cisAB (c. 796A>C)/ABO O. 01. 01, the father's genotype was ABO cisAB (c. 796A>C)/ABO O. 01. 02, and the grandmother's genotype was ABO cisAB (c. 796A>C)/ABO B102. Pedigree analysis indicated that the cisAB allele in this newborn was inherited from his father and grandmother rather than a natural mutation. Homology modeling showed that the side chain orientation and intermolecular forces of Leu266 in the cisAB (p. Met266Leu) transferase changed, and molecular docking demonstrated that the "binding pocket" of the active center of the variant enzyme could accommodate both UDP-GalNAc and UDP-Gal, indicating that the cisAB enzyme structure has bifunctional activity. Conclusion: The bifunctional activity of this cisAB (p. Met266Leu) enzyme is related to the nucleotide variation of c. 796A>C, and molecular docking indicates that the enzyme has dual affinity for A/B sugar donors.

Objective: To perform serological and molecular biological identification of a proband with ABO blood group identified as AwB subtype, and to investigate and analyze the proband's family. Methods: Serological identification of ABO blood groups was performed for the proband and family members using the microcolumn gel assay and saline tube method. Subsequently, PacBio third-generation sequencing was employed to perform full-length sequencing of the ABO gene and haplotype analysis on the proband and her son to accurately determine their genotypes. Results: Serological testing revealed that the proband and her son exhibited the A B subtype phenotype, while the proband's husband had a normal AB type. The results of third-generation sequencing showed that one allele of the ABO blood group in the proband and her son was ABO B.01; the other allele, when compared with the reference sequence ABO A1.01, exhibited a heterozygous mutation of c.297A>G in exon 6, and heterozygous mutations of c.526C>G, c.657C>T, c.703G>A, c.796C>G, c.803G>C, and c.930G>A in exon 7. The c.796C>G mutation resulted in an amino acid substitution of p. Leu266Val in the polypeptide chain, matching the characteristics of the ABO cisAB.09 allele. Therefore, the genotype of the proband and her son was ABO cisAB.09/ABO B.01, with a blood group phenotype of cisAB09 subtype. Conclusion: The combination of serological testing and molecular biological techniques can accurately identify the blood group of patients with ABO subtypes. Family investigation identified two cases of the cisAB09 subtype, demonstrating that the cisAB09 allele can be stably inherited by offspring and remains stable within the family lineage.

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 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 study the molecular biological mechanism for a case of ABO blood group B subtype, and perform three-dimensional modeling of the mutant enzyme. [Methods] The ABO phenotype was identified by the tube method and microcolumn gel method; the ABO gene of the proband was detected by sequence-specific primer polymerase chain reaction (PCR-SSP), and the exon 6 and 7 of the ABO gene were sequenced and analyzed. Homologous modeling of Bw.03 glycosyltransferase (GT) was carried out by Modeller and analyzed by PyMOL2.5.0 software. [Results] The weakening B antigen was detected in the proband sample by forward typing, and anti-B antibody was detected by reverse typing. PCR-SSP detection showed B, O gene, and the sequencing results showed c.721 C>T mutation in exon 7 of the B gene, resulting in p. Arg 241 Trp. Compared with the wild type, the structure of Bw.03GT was partially changed, and the intermolecular force analysis showed that the original three hydrogen bonds at 241 position disappeared. [Conclusion] Blood group molecular biology examination is helpful for the accurate identification of ambiguous blood group. Homologous modeling more intuitively shows the key site for the weakening of Bw.03 GT activity. The intermolecular force analysis can explain the root cause of enzyme activity weakening.

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 Medical Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (Ethics No. 202223).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*& 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.

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.

Objective:To serologically and genotypically analyze the pedigree of a case with a new allele c.175_176insGA of B el subtype and preliminarily explore the molecular mechanism of weak expression of glycosyltransferase B. Method:In the descriptive study,a 23-year-old male voluntary blood donor and his family members were selected for the study. The ABO and Le blood types of the proband and his family members was identified by the test tube method. The agglutination inhibition test was applied to detect the B and H antigens in saliva, and the Sanger sequencing and PacBio (Pacific Bioscience) third-generation haplotype sequencing were performed on the study subjects to identify genotypes. Finally, Expasy software were applied to amino acid translation of DNA sequences and prediction of protein length after gene alteration. ORF finder was applied to predict alternative start codons as well as open reading frames of mRNA, and protein expression mechanisms were analyzed.Results:The proband and her sister were B el subtype, her mother was AB el subtype, her father was normal O type, and all members of the family were Le(a+b+) phenotype. Sanger sequencing results showed that a new allele of c.175_176insGA was found in exon 4 of the proband, her mother, and her sister. Third-generation haplotype sequencing detected the haplotypes of the family members, which revealed that the proband was ABO*O.01.02/ABO*BEL.NEW (c.175_176insGA), the father was ABO*O.01.02/ABO*O.01.02, the mother was ABO*A1.02/ABO*BEL.NEW (c.175_176insGA), and the sister was ABO*O.01.02/ABO*BEL.NEW (c.175_176insGA). Analysis of the protein expression mechanism indicated that although the new allele of ABO*BEL.NEW was presumed to cause a frameshift mutation and result in a premature stop codon p.Asp59Glu*fs20 in exon 5, encoding an inactive glycosyltransferase, an alternative start codon could be utilized to initiate translation of B el subtype functional glycosyltransferase. Conclusion:Expression of the new allele of B el subtype is associated with the translation of B el subtype glycosyltransferase initiated by alternative start codons.