Analysis of ABO gene mRNA expression in peripheral blood of patients with acute myeloid leukemia / 中国输血杂志

【Objective】 To investigate the expression characteristics of ABO gene mRNA in peripheral blood of patients with acute myeloid leukemia. 【Methods】 The RNA-seq data of acute myeloid leukemia in TCGA database and the whole blood RNA-seq data in GTEx database were downloaded. The difference of ABO gene mRNA expression between acute myeloid leukemia and GTEx whole blood samples was analyzed by R software, and the relationship between ABO gene mRNA expression and DNA methylation, immune infiltration and prognosis was analyzed. 【Results】 The expression level of ABO gene mRNA in acute myeloid leukemia(median: 1.333, P25: 3.654, P75: 0.401)was significantly lower than that in the control group(median: 3.576, P25: 3.747, P75: 3.470)(P<0.001). The expression level of ABO gene mRNA in acute myeloid leukemia was negatively correlated with the methylation of + 82(r=-0.249, P<0.001), + 618(r=-0.268, P<0.001), + 1 080(r=-0.105, P<0.001) and + 1 409(r=-0.210, P<0.001) at downstream of transcription start site, and positively correlated with the immune infiltration of nine types of immune cells (B cells, CD8 T cells, Cytotoxic cells, pDC, T cells, T helper cells, Tcm, Tfh and Treg) (P<0.001). There was no significant difference in overall survival between patients with high (median survival time: 366 days, confidence interval: 304-731 days) and low (median survival time: 731 days, confidence interval: 335-1 402 days) expression of ABO gene mRNA in acute myeloid leukemia (P>0.05). 【Conclusion】 The mRNA expression of ABO gene in peripheral blood of patients with acute myeloid leukemia is decreased, which is associated with DNA methylation of the first intron of ABO gene and immune infiltration, but not with the prognosis.

Distribution and molecular basis of A2 subtype in Guangzhou blood donors / 中国输血杂志

【Objective】 To investigate the distribution and molecular basis of A2 subtype among blood donors in Guangzhou. 【Methods】 Whole blood samples of 793 group A blood donors in Guangzhou Blood Center were randomly collected. A2 subtype was screened by anti-A1 lectin in 96-well plate, and ABO typing was confirmed by the tube test. Then, the genomic DNA of A2 subtype blood donors was extracted, and the exons 6-7 of ABO gene were sequenced to determine the genotype of A2 subtype. 【Results】 Among 793 group A blood donors, there were 13 cases of A2 subtype, and the frequency in group A was 1.64%(13/793). The sequencing results of exons 6-7 of ABO gene showed that 10 of the 13 A2 subtypes carried A2 alleles, which were ABO*A2.05/ ABO*O.01.01 (n=5), ABO*A2.05/ ABO*O.01.02(n=2), ABO*A2.01/ABO*O.01.01(n=1) and ABO*A2.01/ ABO*O.01.02(n=2), respectively. The other 3 cases only carried ABO*A1.02 alleles. 【Conclusion】 The main genotype of A2 subtype in Guangzhou is ABO*A2.05, followed by ABO*A2.01.

A Study To Assess The Abo Blood Group Antigen Phenotype And Gene Distribution Among Blood Donors At A Tertiary Care Research Institute In South India

ABO blood group antigens form the basis of current blood transfusion practice and their prevalence among blood donors can provide a glimpse into the population distribution of ABO genes and hence this study was undertaken to assess the ABO antigen phenotype prevalence and ABO gene prevalence among blood donors at a tertiary care teaching research Institute in South India. A total of 49,279 donors have been checked for their ABO blood group. The O, A, B, AB blood group prevalence were 42, 20, 32, 6 percent respectively while the O, A, B gene frequencies were 65, 14, 21 percent respectively.

Association between rs579459 polymorphism of ABO gene and clinical severity of coronary heart disease in Chinese Han population / 中华老年医学杂志

Objective To investigate the association of rs579459 polymorphism in ABO gene with clinical severity of coronary heart disease (CHD) in Chinese Han population. Methods Based on the results of study on the association with CHD conducted by our team ,the rs579459 polymorphism in ABO gene and clinical data of 515 Chinese Han patients with CHD and 908 healthy individuals were collected and analyzed with Plink 1.07 software. Results The rs579459 polymorphism in ABO gene using allele model showed a statistically significant difference between CHD and control group (OR :1.28 ,95％ CI :1.11-1.65 ;P=0.027).When stratified by the severity of CHD ,the rs579459 polymorphism in ABO gene using allele model showed statistically significant difference between the severe CHD group and control group (OR :1.78 ,95％ CI :1.25-2.34 ;P=1.85 × 10-4 ). Conclusions The rs579459 polymorphism of ABO gene is associated with susceptibility to CHD in Chinese Han population ,and also with the severity of CHD.

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.

Two A(weak)B Cases with Aw10 Allele Separated by Allele-specific Sequencing / 대한수혈학회지

We separated an Aw10 allele by allele-specific sequencing in two Aw10/B101 samples that had the AweakB phenotype. Two samples with the A102/B101 genotype were also tested as a control. The reverse primers using position 930 at exon7 were designed for allele-specific sequencing. The differential positions were a total of 52 points for distinguishing the A-allele from the B-allele. Although overlaps with another haplotype allele that showed a minor chromatographic peak were observed in almost all the points, the specific allele-separation rate was 100% (52/52) by assessing the dominance in the chromatographic peak height. Based on the separation rate in the two cases with Aw10/B101 and the two AB controls, allele-specific sequencing is a convenient and reliable method for the separating the A-allele and B-allele in a clinical laboratory.

ABO genotyping in leukemia patients reveals new ABO variant alleles

The ABO blood group is the most important blood group system in transfusion medicine and organ transplantation. To date, more than 160 ABO alleles have been identified by molecular investigation. Almost all ABO genotyping studies have been performed in blood donors and families and for investigation of ABO subgroups detected serologically. The aim of the present study was to perform ABO genotyping in patients with leukemia. Blood samples were collected from 108 Brazilian patients with chronic myeloid leukemia (N = 69), chronic lymphoid leukemia (N = 13), acute myeloid leukemia (N = 15), and acute lymphoid leukemia (N = 11). ABO genotyping was carried out using allele specific primer polymerase chain reaction followed by DNA sequencing. ABO*O01 was the most common allele found, followed by ABO*O22 and by ABO*A103. We identified 22 new ABO* variants in the coding region of the ABO gene in 25 individuals with leukemia (23.2%). The majority of ABO variants was detected in O alleles (15/60.0%). In 5 of 51 samples typed as blood group O (9.8%), we found non-deletional ABO*O alleles. Elucidation of the diversity of this gene in leukemia and in other diseases is important for the determination of the effect of changes in an amino acid residue on the specificity and activity of ABO glycosyltransferases and their function. In conclusion, this is the first report of a large number of patients with leukemia genotyped for ABO. The findings of this study indicate that there is a high level of recombinant activity in the ABO gene in leukemia patients, revealing new ABO variants.

Molecular Characteristics of B Subgroups in Koreans / 대한진단검사의학회지

BACKGROUND: An accurate ABO blood type is essential for transfusion therapy. Genetic structures of ABO blood group and subgroup have been investigated and so far about 100 ABO alleles have been reported worldwide. This study was performed to investigate the molecular characteristics of B subgroups in the Korean population. METHODS: A total of 19 samples of B subgroups were collected from patients (n=11) and from blood donors (n=8) of Korean Red Cross blood centers; these samples had been typed serologically for the ABO blood group. Allele-specific polymerase chain reaction (PCR), direct sequencing of exon 6 and 7, and allele separation were performed for ABO gene analysis. RESULTS: The ABO PCR-RFLP genotyping results of 18 samples among the provisional 19 B subgroups were identical regardless of their phenotypes. Two new B alleles showing 255C>T base change and 547G>A base change were observed in B3 and A1B3 subgroups. CONCLUSIONS: Serologically unidentified B subgroups were unequivocally identified through molecular analyses of the ABO gene. And new ABO alleles observed only in the Korean B subgroups were recognized.

Detection of a Hybrid A int Allele by PCR-RFLP / 대한수혈학회지

No abstract available.

Molelular genetic analysis of Ael variant phenotype of ABO blood group system / 대한수혈학회지

BACKGROUND: Since the genes encoding glycosyltransferases synthesizing ABO antigens were cloned and sequenced in 1990, genetic polymorphisms and phenotype-genotype correlations have been reported by several investigators, but the genetic basis remains unclear for many subgroups. The Ael phenotype is one of the important A subgroups having very weak A antigen, and recent studies suggested that different alleles can result in this phenotype. METHODS: Three unrelated Ael subgroup samples from Korean blood donors were studied. Exons 6 and 7 of the ABO gene, 91% of the catalytic active part of the glycosyltransferase, were amplified and subjected to direct sequencing. RESULTS: Only C467T substitution in comparison with the consensus sequence of A gene was found in one Ael sample, but this mutation pattern was very commonly observed in normal A1 phenotype of Orientals. The other two samples had T646A (Phe216Ile) and G681A (silent) substitutions beside C467T substitution, reported first from a Japanese Ael individual. CONCLUSIONS: These results indicate that molecular genetic heterogeneity within the Ael subgroup was also seen.

Molecular Characteristics of A Subgroups in Koreans / 대한수혈학회지

BACKGROUND: An exact ABO blood type is essential for transfusion therapy. Genetic structures of ABO blood group and subgroup have been investigated and about 100 ABO alleles have been reported worldwide. This study was performed to investigate the molecular characteristics of A subgroups in the Korean population. METHODS: Nine A and five AB subgroups were collected from patients and from blood donors of Korean Red Cross blood centers after serological ABO blood group typing. On these samples, allele-specific polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), direct sequencing of exon 6 and 7, and allele separation were performed for ABO gene analysis. RESULTS: The ABO PCR-RFLP genotyping results of 13 samples among the provisional 14 A subgroups were identical with their phenotypes. ABO*A205 allele was observed in an Aint subgroup. Two new A alleles that showed 784G>A base change and 990C>T of intron 6. And a polymorphism of 532C>T in A(pro) intron 5 were also discovered. Conclusion: Through the molecular analysis of this study, serologically unidentified A subgroups were obviously identified. And the new alleles only observed in the Korean A subgroups were recognized.