Molecular mechanism and bioinformatics analysis of 9 samples with rare RhD variants / 中国输血杂志

【Objective】 To study the molecular mechanism of 9 samples with rare RhD variants and their RhD epitopes and protein structure. 【Methods】 The 9 blood samples with rare RhD variants were collected from 210 644 blood donors of Shenzhen Blood Center. Regular serological assaying was used for determination of Rh type for the 9 samples. Indirect anti-human globulin test (IAT) was used to confirm the RhD antigen and to screen the antibodies. D-screen reagent was sued to analyze the RhD epitopes of the samples. RHD zygosity testing of the samples was detected by PCR-SSP. The nucleotide sequences of all 9 exons and adjacent flanking intron regions of RHD gene were sequenced. The prediction of the effects of mutations on RhD protein function were analyzed using PROVEAN, SIFT, PolyPhen-2 and MutationTaster software. Robetta and Swiss-PdbViewer 4.1.0 were used for modeling the tertiary structures of RhD. 【Results】 A total of 9 individuals with rare RhD variants were identified as follows: RHD*weak D type 25, RHD*weak D type 50, RHD*weak D type 95, RHD*weak D type 12, RHD*weak D type 128 and four novel RHD alleles. The prediction of the tertiary structures showed that the RhD protein conformation was disrupted in the 9 rare RhD variants samples. 【Conclusion】 Five rare and four novel RHD alleles have been identified. Their phenotypic and genotypic descriptions enrich the database of reported RHD alleles. Bioinformatics analysis provided evidences for further study of the structure and functions of RhD protein.

Diagnosis and genetic analysis of severe neonatal anemia caused by α-Thalassemla combined with cold IgG anti-M / 中国输血杂志

【Objective】 To investigate the family inheritance of α-Thalassemla gene and the risk of severe anemia in neonates caused by cold IgG anti-M. 【Methods】 ABO, Rh, MN blood groups and the specificity of unexpected antibody were identified by blood group serology. The IgG subtype and antibody titer of anti-M antibody were detected. The etiology of neonatal hemolytic disease was identified by three tests and α-Thalassemla gene diagnosis. 【Results】 Family investigation showed that father was B, CCDee, MN with no α-Thalassemla gene detected; Mother B, CcDee, NN, carrying α-Thalassemla gene; both the proband and his brother were B, CCDee, MN, carrying α-Thalassemla gene. Cold IgG anti-M was present in plasma of both the mother and the proband. The titer of the mother was 128 and that of the proband was 64. The subtype of IgG anti-M was IgG1 and IgG3. The direct anti-globulin test, release test and free test of the proband and his brother were negative, and the diagnosis was severe anemia and hemolysis caused by α-Thalassemla combined with cold IgG anti-M. 【Conclusion】 The direct antiglobulin test of neonatal hemolytic disease caused by IgG anti-M can be negative or weakly positive, and α-Thalassemla gene could be hereditary in families. The presence of α-Thalassemla gene can cause anemia, hemolysis and splenomegalysis in neonates, which could be aggravated when accompanied by cold-type IgG anti-M. In the presence of high-valency IgG antibody in plasma, blood exchange combined with transfusion can improve the curative effect.

Solutions to cross-matching incompatibility in clinical: retrospective study of 1 770 cases in Shenzhen / 中国输血杂志

【Objective】 To analyze the blood samples sent by hospitals in Shenzhen to solve ABO cross-match incompatibility during 2011 to 2020, so as to find corresponding solutions to improve the efficacy of blood transfusion. 【Methods】 The clinical data of 1 770 cases of cross-match incompatibility in our laboratory from January 2011 to December 2020 were collected and reviewed. The causes of cross-match incompatibility were analyzed, the types of unexpected antibodies were determined. The overall incidence of antibodies was evaluated by statistical method of classified variables. The safety of blood transfusion was safeguarded by ABO homotype plus cross-matching compatibility. 【Results】 1) The 1 770 samples, presenting cross-matching incompatibility, involved 956 patients. The average number of cross-matching per patient from 2011 to 2015 was 1.32(307/232), which increased from 1.27(103/81) in 2016 to 2.23(286/128) in 2018, and remained stable in 2019 and 2020. 2) Among 956 patients, auto-and/or allo-antibody in plasma were yielded in 90.38%(864/956), including auto-antibody plus alloantibody in 42.26%(404/956), solo auto-antibody in 20.71%(198/956) and solo allo-antibody in 27.41%(262/956). Up to 20 kinds of specific allo-antibodies were detected, belonging to 8 blood groups. Among them, 70.82%(551/778) were Rh blood group, such as anti-E(37.15%)>anti-c(20.95%)>anti-C(5.27%)=anti-e(5.27%)>anti-D(2.19%), followed by MNS [11.40%(112/778)], Kidd [5.66%(44/778)], Leiws [3.21%(25/778)], Duffy [1.80%(14/778)], Diego [1.03%(8/778)], P1 [0.39%(3/778)] and H [0.26%(2/778)]. 3) 86%(37/43) of multiple transfusion recipients, aged below 20 years old, were thalassemia, and 1-4 kinds of allo- and/or auto-antibody were yielded. 【Conclusion】 The cross-matching incompatibility were mainly caused by allo- and/or auto-antibodies, which may be induced by blood transfusion, pregnancy or autoimmune diseases such as autoimmune hemolytic anemia.Those suspicious blood samples in clinical should be sent to blood group reference laboratory for further determination, in order to ensure the safety and efficacy of blood transfusion.

Methylation of CpG island in ABO gene promoter coding glycosyltransferase with dual donor specificity / 中国组织工程研究

BACKGROUND:During the research of ABO blood type antigen, the overwhelming majority samples of same ABO gene express a normal and same ABH antigen. But a certain amount samples with the same ABO genetic background show different antigen intensity expression as for different family or individuals. The ABO blood type has complex expression regulation mechanism. Analysis of ABO blood group serology and genetic background of these rare bi-specific AB phenotype specimens, and further studying on epigenetics may partly revealed ABO gene expression mechanism. OBJECTIVE:To study methylation of CpG island and explore the relationship between ABO gene promoter coding glycosyltransferase with dual donor specificity and ABH antigen expression. METHODS:Six samples detected as CisAB or B(A) phenotype were studied in this paper. The whole code sequences and promoter sequence of ABO gene were amplified respectively. The level of CpG methylation in promoter of ABO gene was further detected with bisulfite treatment method. RESULTS AND CONCLUSION:Among the six bi-specific AB phenotype samples, two previously-identified CisAB05/B(A)06 al eles with nt803C>G on the basis of B101 al ele sequence could be seen, and three additional methylated sites nt-33(30%), nt+27(50%) and nt+49(50%) were found between the two regions of CpG island in promoter of ABO gene. Two CisAB01 al eles with nt803C>G mutation on the basis of A101 sequence were found at nt-26C(10%). Other two B(A)04 al eles contained nt640A>G mutation on the basis of B101 sequence were found in the whole code sequences regions, and six additional methylated sites nt-33(10%), nt+16(50%), nt+57(60%), nt+59(60%), nt+68(60%) and nt+74(60%) were found between the two samples. No abnormity was identified in the promoter region of ABO gene. Our results indicated that the differential methylation levels in the CpG island of ABO gene promoter region may affect ABH antigens expression on the red cel membrane even if the samples had the same ABO genetic background.

Study on the gene polymorphism of Auberger antigens in Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the gene polymorphism of the Auberger antigens in Lutheran blood group system in Chinese population and establish a stable, accurate molecular method detecting Auberger antigens.</p><p><b>METHODS</b>Peripheral blood samples from 162 randomly collected and unrelated volunteer blood donors were directly sequenced for the exon 12 at the gene locus of Auberger antigens. PCR products with novel nucleotide were further investigated by restriction fragment length polymorphism (RFLP) analysis.</p><p><b>RESULTS</b>Auberger genotypes in the 162 Chinese individuals were obtained: Au(a+ b- )(nt1615A) was found in 119 individuals, Au(a+ b+ ) (nt1615A/G) in 40 individuals and Au(a- b+ ) (nt1615G) in 3 individuals. The allele frequencies of the Au(a) and Au(b) were 0.8580 and 0.1420, respectively. An individual with homozygous Au(a) genotype had a nucleotide mutation (1595 G to T). The mutation was confirmed by digesting the DNA with Hha I.</p><p><b>CONCLUSION</b>The distribution of gene polymorphism of Auberger antigens in a Chinese population was investigated and obtained. And a molecular method determining the Auberger antigen was established. A novel Lutheran allele was deposited in GenBank (accession number EU260043).</p>

Identification of novel B(A)803 C→G allele mutation in Chinese population and induction of severe hemolytic disease of the newborn / 中华检验医学杂志

Objective To investigate serological blood typing of the ABO locus which contradict to general law of inheritance in parentage,and the underlying reasons for severe hemolytic disease of newborn(HDN).Methods To research the family whose newborn is AB phenotypes,mother is O phenotypes and father is AB phenotypes.The familiy were genotyped by parentage tests, serological tests,PCR-SSP and direct DNA sequencing at exons 6 and 7 of ABO gene.At the salne time,HDN was detected by micro column gel Coombs (MGCT), and the primary fingerposts of the routine blood tests. Biochemical tests were dynamically observed.Results The results of parentage tests showed that three-generation pedigree have parent-child relationship. The red blood cell(RBC)of this AB phenotypes of this family members strongly agglutinated(4+)with diverse monoelonal anti-A and anti-B antibodies,and their serum did not contain anti-A and anti-B antibodies in blood anti-typing.PCR-SSP can not detect their A and B gene,but DNA sequencing at exons6 and 7 of ABO gene revealed that it had the B(A)803C→G mutation.Conclusions The genetm basis of this parentage are B(A)803G blood gene which harbored both A and B difunctionality of glyeosyhransferases.This was the first report that severe HDN resulting from a large number of A and B antigens in RBC of B(A)phenotype of a newborn,which has clinical significance on ABO locus.

The relationship of Bel subgroup and the G952A mutation of the α1,3 galactosyltransferase gene / 中华检验医学杂志

Objective To study the molecular genetic background of Bel subtype at ABO blood group.Methods Three samples and fifteen samples were diagnosed as Bel subgroup and normal control samples by serological test,respectively.The extracted DNA was genotyped by sequence specific primer- polymerase chain reaction foilowed by sequencing for Exon6 and exon7 at ABO locus and clones were sequenced.Results A novel Bel variant allele(GenBank EF117687) was identified in a Bel individual.The Bel allele was different from the regular B101 allele by single 952G>A missense mutation in exon7.resulting in an amino acid subsfitution of Val for Met at 318 locus.No mutations were detected in the fifteen control samples and the other two Bel allele samples.Conclusions The mutation position was fimt found to lie on coding region of ABO gene behind nucleotide 930.The mutation of G952A in the al,3 galactosyhransferase gene may be one of the molecular genetic basis of Bel ohenotype.

Identification of a novel B variant allele in a Chinese Han individual with B subgroup / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the molecular genetic background of B subtype in Chinese Han population and identify novel allele at the ABO locus.</p><p><b>METHODS</b>Ten samples from randomly selected blood donors of normal B phenotype used as control, and six samples from individuals diagnosed as B subgroup by serological tests were genotyped by sequence specific primer polymerase chain reaction and direct DNA sequencing at the exons 6 and 7 of ABO gene. The exons 6 and 7 and the intervening intron 6 of the B allele from each B subgroup sample were analyzed by cloning and haplotype sequencing.</p><p><b>RESULTS</b>A novel B variant allele was identified in two individuals whose blood samples were diagnosed as belonging to Bx subgroup and Bw subgroup respectively, the novel B allele being different from the allele B101 by single 695T>C missense mutation in exon 7. A family with the individual possessed Bx subgroup was studied. Among 22 family members tested, seven family members were found to carry the novel B variant allele. No novel point mutation at the exons 6 and 7 of ABO gene were detected in the ten control samples and the other four samples with B subgroup.</p><p><b>CONCLUSION</b>The present authors define this allele as a novel B variant allele. The mutation of this novel allele, in which the nucleotide alters from T to C at position of 695 in exon 7 and hence results in an amino acid change from Leu to Pro, is expected to diminish the enzyme's activity. It indicates that the alteration of amino acid at the position of 232 is critical to the activity of glycosyltransferases.</p>

Genotyping of ABO blood group in Chinese Han population / 中国组织工程研究

BACKGROUND: ABO is the most important blood group system for blood transfusion. Though widely used in determining ABO blood group for its simplicity and rapidity, serological technology has its inherent limitation, for which ABO genotyping provides a valuable alternative.OBJECTIVE: To study ABO gene polymorphism in Chinese Han population and apply ABO genotyping technique to solve serological problems in clinical practice of blood transfusion.DESIGN: Comparison of ABO genotyping results of random selected samples with those of routine serological phenotyping.SETTING: An institute of transfusion medicine in a municipal blood center.PARTICIPANTS: Totally 260 unrelated healthy Chinese blood donors of Han nationality were randomly selected in Shenzhen Blood Center from March to December in 2002, including 110 male and 150 female subjects aged between 18 and 50 years. A sample with discrepancy in serological ABO phenotype was from our blood center, and the donor' s family was investigated. Six samples suspected to be A2 phenotype by serological test were from four hospitals in Shenzhen including the Second People' s Hospital of Shenzhen.METHODS: The DNA was extracted from the peripheral blood by rapid salt fractionation, and subjected to polymerase chain reaction(PCR) with sequence-specific primers (PCR-SSP) to amplify the ABO gene for ABO genotyping. The alleles of the blood type difficult to determine were amplified with PCR-SSP on the basis of serologic tests including absorption and elution test and agglutination inhibition assay of salivary blood-group substances.MAIN OUTCOME MEASURES: Genotypes and phenotypes of the blood samples from 260 individuals and of the samples with serological ABO discrepancy.RESULTS: In the 260 Chinese Han individuals, in accordance with Hardy-Weinberg equilibrium, the gene frequencies of O1, B, A1O1(A467c), A1O2/1O3(A467T) alleles were 0. 582 7, 0. 184 6, 0. 009 6, and 0. 2231, respectively. Two of the six individuals with difficulty of blood type determination and suspected to have A2 phenotype by serological tests proved to have A2O1O1 genotype, and the rest were all of A1O2/A1O3O1. Three children of a family with difficult identification were para-Bombay types, and their ABO types were A102B, A102B and A102O1, respectively.CONCLUSION: ABO PCR-SSP genotyping is simple, rapid and accurate and can be a valuable complement to serological identification.

A novel O~1 variant allele at the ABO blood group locus / 中华检验医学杂志

Objective To identify novel ABO allele in Chinese population. Methods The ABO blood group was tested by serological method, and then genotyped by sequence-specific primer (PCR-SSP) , gene cloning and sequence analysis. Results A healthy blood dornor who was diagnosed as having A2 subgroup and A2O1genotype was subjected to ABO gene cloning and sequence analysis. The haplotype-specific sequence analysis indicate that two single-base deletions, where G-deletion at nucleotide position 261 and A-deletion at nucleotide position 496 were determined in the O1 allele. The nucleotide sequence of the novelO1 allele were identical to ABO 0101 allele except for A-deletion at nucleotide position 496 in exon7 of ABO locus. Conclusion We defined this 0 allele as a novel O1 variant allele, and its registered number by GenBank is AY374123.

Study on the FUT2 gene structure of Xinjiang Uighur people of China / 中国输血杂志

Objective To study the Secretor gene (FUT2) molecular structure of Uighur population in Xinjiang area,China. Methods DNA was extracted from 40 Uygur unrelated donors' blood and sequence analysis of FUT2 genes was performed. Results Four mutations in the FUT2 genes of Uighur donors have been identified. The frequencies of mutations were 71.25% for 357T, 28.75% for 357C,77.50% for 385A,22.50% for 385T,70% for 428G,30% for 428A,72.50% for 739G and 27.50% for 739A. Conclusion Based on the characteristics of FUT2 gene structure of Xinjiang Uighur,it cauld be thought that there are some relationships between Xinjiang Uighur, Taiwanese of China and Caucasiany.

Study of the Association of diabetic retinopathy with 2 candidate genes / 中国输血杂志

Objective To study the relationship between diabetic retinopathy(DR) and Landsteiner-Wiener,Indian blood group genes.Methods Peripheral blood samples were collected from 50 DR patients,and 160 unrelated volunteer blood donors(the control).CDNA,including LW gene generated by reverse transcription polymerase chain reaction(RT-PCR),was subjected to sequence analysis,and the genomic DNAs,extracted from each sample,were sequenced directly for LW gene and IN gene.Woolf method was used for calculating relative risk(RR).Results In the 160 control samples,there was A at the nt380 locus in Exon1 of the LW gene,which were genotyped as LWa;and there was G at the nt252 locus in Exon2 of the IN gene,which were genotyped as INb.All the 53 samples from DR patients were LWa homozygous genotypes and all INb homozygous genotypes.Conclusion These two candidate genes are not associated with the incidence of DR.

Identification of a novel Bx allele in a Chinese Han individual with B subgroup / 中国输血杂志

T missense mutation in exon 7. No novel point mutation at exons 6 and 7 of ABO gene was detected in the other four samples with B subgroup. Conclusion We define this allele as a novel B allele in Chinese Han individuals. The mutation of this novel allele in which the nucleotide changes from C to T at position 721 in exon 7, resulting in an amino acid change from Arg to Trp, results in the decrease of the enzyme activity. It indicates that the alteration of amino acid at position of 241 is critical to the activity of glycosyltransferases.

Mutational analysis of FUT1 and FUT2 genes in para-Bombay individuals / 中国输血杂志

Objective To study the mutation of FUT1 and FUT2 genes in para-Bombay individual.Methods Direct DNA sequencing of FUT1 and FUT2 gene coding region were analyzed in two individuals with para-Bombay phenotype.Results One individual lost one of the three AG repeats located at nucleotides 547~552 of the FUT1 gene, whereas two of the three T repeats located at nucleotides 880~882 were deleted in the other.Conclusion Two frame-shift mutations of FUT1 gene are responsible for the H antigen deficiency

A study of FUT2 gene point mutation in the Chinese Han Population / 中国输血杂志

Objective To study the point mutation of FUT2 gene in Chinese Han population.Methods Using direct sequencing,molecular cloning techniques and the comparing with the gene sequence reportedby Kelly, the FUT2 gene structures of 41Chinese Han individuals have were studied.Results The G428A mutations of FUT2 gene was not found,but the A385T and C357T mutations were found in the 41 Chinese Han individuals.Among the 41 individuals,24 had A385T mutation and 17 had no A385T mutation.The neutral mutation C357T was found in all 41individuals.Conclusion The G428A point mutation of FUT2 which is commonly found in non secretor of Africans and Caucasian was not found in Chinese population.There are A385T and C357T point mutations which were found in 41 Chinese Han individuals.The present stady shows the difference between Chinese and Caucasian,and other non secretor mutations will be revealed by further investigation

Allele-related variations in the CCAAT-binding factor/NF-Y enhancer region of the A_2 blood group / 中国输血杂志

A)at nt.41 of the only one repeat in 15 individuals with the A205 allele were detected.No special molecular background was found in the two samples which were phenotyped as A2,but genotyped as A102/B101.Conclusion CBF/NF-Y enhancer region of the A2 alleles occurs with minisatellite fragments length polymorphisms.Allele-specific variations in CBF/NF-Y enhancer region of A2 blood group gene were elucidated in Chinese population.