OBJECTIVETo investigate the molecular basis of an individual featuring weak A phenotype of ABO blood group system.

METHODSSerologic investigations, serum transferases activity assay and absorption-elution test were carried out to identify the ABO blood group. The 7 exons and flanking introns of ABO glycosyltransferase gene were amplified with polymerase chain reaction (PCR). The products were sequenced bidirectinally following enzyme digestion. Haplotypes of exons 6 and 7 of the ABO gene were analyzed.

RESULTSA weak A antigen was identified on red blood cells of the proband. Eight heterozygous sites in exons 6 and 7 (261delG 297A/G, 421C/T, 467C/T, 646T/A, 681G/A, 771C/T, 829G/A) of the ABO gene were identified. Based on haplotype analysis, one allele was determined as O02, while a novel mutation 421T>C was identified in another allele, which resulted in the amino acid change Ser141Pro of the A glycosyltransferase.

CONCLUSIONAbove results suggested that amino acid substitutions resulted from a novel mutation 421T>C of the ABO gene may decrease the enzymatic activity and result in the weak A phenotype.

ABO Blood-Group System ; genetics ; Adult ; Alleles ; Female ; Humans ; Mutation ; N-Acetylgalactosaminyltransferases ; genetics

OBJECTIVETo explore the effect of variants of alpha-1,3-N-acetylgalactosaminyltransferase of the ABO gene on A antigen expression.

METHODSThree samples were assayed by serological method. The extracted DNA was genotyped by sequence-specific primer polymerase chain reaction (SSP-PCR) and direct sequencing. To identify haploid of the ABO gene, clones for exons 6 and 7 of the ABO locus were analyzed.

RESULTSAll of the three samples were identified as the Ael subgroup, among which were found to carry the Ael08 and O01 alleles, while another was confirmed to harbor the Ael08 and O04 alleles. Compared with the A101 allele, two nucleotide alterations (467C>T and 804insG) at exon 7 have resulted in amino acid substitution P156L and frameshift from position 269.

CONCLUSION467C>T and 804insG variants of the alpha-1,3-N-acetylgalactosaminyltransferase gene probably underlie the Ael phenotype.

ABO Blood-Group System ; genetics ; Alleles ; Female ; Humans ; Male ; N-Acetylgalactosaminyltransferases ; genetics

OBJECTIVE: To explore the genetic basis for a Chinese pedigree with a novel ABO subtype. METHODS: The proband and his family members were subjected to serological analysis, and their genotypes were determined by fluorescence PCR and direct sequencing of the coding regions of the ABO gene. Exons 6 to 7 of the ABO gene were also subjected to clone sequencing for haplotype analysis. RESULTS: The proband was determined as an AxB subtype. By fluorescence PCR, he was typed as A/B. Clone sequencing has revealed a insertional mutation c.797_798 insT in exon 7 of the ABO gene, which yielded a novel allele. Pedigree analysis confirmed that the novel ABO*A1.02 allele carried by the proband and his sister was inherited from their father. The c.797_798insT mutation has been submitted to GenBank with an accession number of MK125137. CONCLUSION The c.797_798insT mutation of exon 7 of the ABO gene probably has led to weakened expression of A antigen.
ABO Blood-Group System/genetics* ; Alleles ; China ; Genotype ; Humans ; Male ; Mutation ; N-Acetylgalactosaminyltransferases/genetics* ; Pedigree

OBJECTIVETo explore the effect of alpha-1,3-N-acetylgalactosaminyltransferase gene variants on A antigen expression in a family where a member was suspected for a rare A3 subtype of the ABO variant.

METHODSSerological assay was carried out to determine the ABO blood group of the proband and his family members. To determine the haploid of the alpha-1,3-N-acetylgalactosaminyltransferase gene of the proband, DNA was extracted and genotyped with sequence-specific primer PCR (PCR-SSP) followed by direct sequencing and cloning of exons 6 and 7 of the ABO locus.

RESULTSWeak A antigen was detected on red blood cells of the proband, while anti-A and anti-B antibodies were detected in his serum. DNA sequencing showed a 261delG mutation in exon 6, and two heterozygote mutations (467C>T and 745C>T) in exon 7 of the alpha-1,3-N-acetylgalactosaminyltransferase gene. Haplotype analysis has identified two alleles A307 and O01. Compared with the A101 allele, the A307 allele has harbored two nucleotides changes (467C>T and 745C>T), which resulted in substitution of two amino acids (P156L and R249W).

CONCLUSIONThe 467C>T and 745C>T mutations of the alpha-1,3-N-acetylgalactosaminyltransferase gene can result in an A307 phenotype with reduced expression of A antigen.

ABO Blood-Group System ; genetics ; Alleles ; Child ; Humans ; Male ; Mutation ; genetics ; N-Acetylgalactosaminyltransferases ; genetics ; Sequence Analysis, DNA ; methods

This study was purposed to analyses the serological and molecular basis of one sample of A blood group which has anti-A. The tube method was used to detect the blood group phenotype, the genotype was amplified by PCR-SSP. The sequence of a-1-3-N-acetylgalactosaminyltransferase gene of blood group was determined by Sanger method. The results showed that serological results of blood group were discrepant. It was determined as A subtype firstly. The result of PCR-SSP showed the existence of O and A blood group gene. The sequencing result of the 6th exon of ABO gene showed the existence of c.261delG, which refers to the O gene. The specific amplification sequencing analysis was carried out on the 7th exon of the O and A blood group gene. Two mutations in the 7th exon of the A gene haplotype, c.467 C > T and c.626 G > A, four mutations in the 7th exon of the O gene haplotype, c.646T > A, 681G > A, 771C > T, 829G > A had been detected. It is concluded that a novel allelic mutation c.626 G > A in the 7th exon of A gene is explored. The Genbank access number of this novel mutation is KC690281. c.467 C > T is SNP. The combination of two allele mutation of A gene is named as a new allelic subtype A311.
ABO Blood-Group System ; genetics ; immunology ; Blood Grouping and Crossmatching ; Exons ; Female ; Genotype ; Humans ; Mutation ; N-Acetylgalactosaminyltransferases ; genetics ; Phenotype ; Polymorphism, Single Nucleotide ; Young Adult

The objective of this study was to analyze the molecular genetic basis for 2 individuals with A2B phenotype of ABO subtype. The ABO group antigens on red blood cells were identified by monoclonal antibodies and the ABO antibodies in serum were detected by the standard A, B, O cells. The exon 5 to exon 7 coding region of ABO gene was amplified by polymerase chain reaction (PCR) and the PCR product was sequenced directly after the enzymes digested. The amplified product was also cloned by TOPO TA cloning sequencing kit to split the 2 alleles apart and chosen colonies were sequencing bidirectionally for exon 6 to 7 of ABO gene. The results showed that both A and B antigen were identified on red blood cells of the individuals and there was anti-A1 antibody in their serum. There was no 261G deletion and showed 297A/G, 467C/T, 526C/G, 657C/T, 703G/A, 742C/T, 796C/A, 803G/C, 930G/A heterozygotes by direct DNA sequencing. After cloning and sequencing, it was obtained the B101 and one novel A allele. The novel allele has one nucleotide change at 742 position C to T compared with A102, which results in an amino acid Arg to Cys at 248 position and was nominated as A213. It is concluded that C742T mutation of the α1, 3 N-acetyl-D-galactosaminyl-transferase gene can lead to A2 phenotype and with anti-A1 antibody in serum.
ABO Blood-Group System ; genetics ; immunology ; Alleles ; Antibodies, Anti-Idiotypic ; immunology ; Blood Donors ; Exons ; Genotype ; Heterozygote ; Humans ; Molecular Sequence Data ; Mutation ; N-Acetylgalactosaminyltransferases ; genetics ; Phenotype ; Sequence Analysis, DNA

OBJECTIVETo study the serological characteristics and molecular mechanism for a rare Pk phenotype of the P1Pk blood group system.

METHODSThe blood group of the proband was identified by serological techniques. The coding region and flanking intronic sequences of the β-1,3-N-acetylgalactosyltransferase gene (B3GALANT1) associated with the Pk phenotype were analyzed using polymerase chain reaction sequence-based typing.

RESULTSThe proband was identified as having a rare Pk phenotype including anti-P in her serum. The blood group of her daughter and husband showed a P2 phenotype. The nucleotide sequences of the B3GALANT1 gene of her husband and two randomly-chosen individuals were the same as the reference sequence (GenBank AB050855). Nucleotide position 433 C>T homozygous mutation in the B3GALANT1 was found in the proband, which has resulted in a stop codon at amino acid position 145, which may produce a premature protein capable of decreasing or inhibiting the activity of the β -1,3-N-acetylgalactosyltransferase. The nucleotide position 433 C/T heterozygous in the B3GALANT1 was found in her daughter.

CONCLUSIONThe Pk phenotype resulted from 433 C>T mutation in the B3GALANT1 gene has been identified.

ABO Blood-Group System ; genetics ; Adult ; Base Sequence ; Blood Grouping and Crossmatching ; Female ; Genotype ; Humans ; Male ; Molecular Sequence Data ; N-Acetylgalactosaminyltransferases ; genetics ; Pedigree ; Phenotype ; Point Mutation

OBJECTIVETo analyze the serological features and related blood group genes of a donor with A subtype of the ABO blood type.

METHODSThe ABO blood group of the sample was determined, in addition with the activity of blood group glycosyltransferase and blood group secretory substances. Sanger sequencing was adopted to analyze the genotype of the blood group.

RESULTSThe proband was identified as A subtype (non-secretory type), with no detectable activities of a 1, 3-N-acetylgalactosyltransferase. DNA sequencing has identified a number of mutations including nt.261del/G and 297A/A of exon 6, and nt.467C/T, 806T/C and 1009A/G of exon 7. Clone sequencing has confirmed that the nt.806T>C exists at one allele and was a novel mutation. The proband genotype was A205/Onew (806T>C). The nt.806T>C of the exon 7 was confirmed to be a novel mutation, which was given a GenBank accession number KP341759. Family study showed that the genotype of the proband's father was Onew (806T>C)/O02, and that of his mother was A101/A205. The novel mutation of the proband has derived from his father.

CONCLUSIONThe reduced A antigenicity of the sample was due to the A205 subtype allele and the presence of a novel O allele.

ABO Blood-Group System ; genetics ; Adult ; Base Sequence ; Blood Grouping and Crossmatching ; Exons ; Female ; Genotype ; Humans ; Male ; Molecular Sequence Data ; Mutation ; N-Acetylgalactosaminyltransferases ; genetics ; metabolism

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with recurrent fetal hydrocephalus. METHODS: A couple who had presented at the Affiliated Hospital of Putian College on March 3, 2021 was selected as the study subject. Following elective abortion, fetal tissue and peripheral blood samples were respectively obtained from the abortus and the couple, and were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. RESULTS: The fetus was found to harbor compound heterozygous variants of the B3GALNT2 gene, namely c.261-2A>G and c.536T>C (p.Leu179Pro), which were inherited from its father and mother, respectively.According to the guidelines of American College of Medical Genetics and Genomics, both variants were classified as pathogenic (PVS1+PM2_Supporting; PM3+PM2_Supporting+PP3+PP4). CONCLUSION The compound heterozygous variants of the B3GALNT2 gene probably underlay the α-dystroglycanopathy in this fetus. Above results have provided a basis for genetic counseling of this pedigree.
Female ; Humans ; Pregnancy ; Aborted Fetus ; Asian People/genetics* ; East Asian People ; Fetus ; Genetic Counseling ; Mutation ; N-Acetylgalactosaminyltransferases ; Pedigree ; Walker-Warburg Syndrome/genetics*

OBJECTIVETo explore the molecular basis for a rare Ax13B phenotype of the ABO subtype.

METHODSSerological assays were carried out to characterize the erythrocyte phenotype of the discrepant sample. Exons 6 and 7 of the ABO gene were amplified with polymerase chain reaction and subjected to direct sequencing. The amplicons were also cloned to separate the two alleles.

RESULTSBoth A and B antigens were detected on the red blood cells of the proband, and anti-A antibody was detected in the serum. The serological phenotype of the sample was identified as AxB. DNA sequencing showed heterozygous status for 297AG, 526CG, 657CT, 703AG, 796AC, 803GC, 930GA and 940AG in exons 6 and 7. After cloning and sequencing, two alleles Ax13 and B101 were obtained. The sequence of Ax13 showed a nucleotide change (A to G) at position 940.

CONCLUSIONThe 940A>G mutation of the α-1,3-N-acetylgalactosaminyltransferase gene has resulted in the reduced expression of A antigen.

ABO Blood-Group System ; genetics ; Alleles ; Base Sequence ; Blood Grouping and Crossmatching ; methods ; Exons ; genetics ; Genotype ; Genotyping Techniques ; methods ; Heterozygote ; Humans ; Male ; N-Acetylgalactosaminyltransferases ; genetics ; Phenotype ; Point Mutation ; Sequence Analysis, DNA ; methods