Genotyping of the rare Para-Bombay blood group in southern Thailand

ABSTRACT Introduction: The para-Bombay phenotype, or H-deficient secretor, results from different mutations of the FUT1, with or without the FUT2 mutation. Consequently, there is an absent or weak expression of the H antigen on red blood cells (RBCs). Routine ABO blood grouping for two siblings with blood group O showed discrepant results with their parental blood group AB. Fragments encompassing the entire coding region of the FUT1 and FUT2 genes were investigated. Methods: Blood and saliva specimens were collected to verify the correct ABO grouping by cell grouping, serum grouping and the hemagglutination inhibition (HI) test, respectively. The FUT1 and FUT2 genomes were identified using the whole-exome sequencing (WES) in two children's DNA blood specimens and may have caused, or been relative to, their blood group. Genetic variations of the FUT1 and FUT2 genes have been investigated in the other family members using the Sanger sequencing. Results: The serologic reaction results of the proband revealed that A, B and H antigens were absent on RBCs, and that the serum contained anti-H. However, ABH and AH antigens were present in the saliva PB1 and PB2, respectively. The probands PB1 and PB2 were assigned as AB and A blood groups, respectively. Blood genotyping confirmed that heterozygous mutations of the FUT1 gene, c.551_552delAG, were identified. Three family members, PB3, PB, and PB8, also showed normal ABO blood groups, but their genotypes were also the FUT1 mutation c.551_552delAG. Conclusions: The FUT1 mutation c.551_552delAG may result in the reduced or absent H antigen production on RBCs, which characterizes the para-Bombay phenotypes. Blood genotyping is essential if these individuals need a blood transfusion or are planning to donate blood.

Progress on FUT2 gene and gut microbial composition in relation to rotavirus susceptibility / 国际儿科学杂志

Rotavirus(RV) is currently the leading cause of severe diarrhea in infants and young children worldwide, and RV has been found to recognize and bind to histo-blood group antigens(HBGAs) through its structural protein VP8, and the FUT2 gene determines the expression of HBGAs in epithelial tissues and secretion in body fluids.Individuals with loss of functional enzyme activity due to mutations in the FUT2 gene, called non-secretors, are unable to express and secrete HBGAs in the mucosa and body fluids, and non-secretors have been found to be resistant to diarrhea caused by RV.Studies have shown that microbial composition is genetically regulated by the host, and hundreds of genetic loci are involved in regulating the composition of human gut microbes, including FUT2.Sterile animal models reduce the rate of RV infection, suggesting that intestinal bacteria are associated with the process of RV infection.These studies reveal that secretory status directly influences individual susceptibility to RV, and its effect on gut microbial composition indirectly modulates human susceptibility to RV.This article reviews the correlation between FUT2 and gut microbial composition with RV susceptibility, with the aim of opening new avenues for personalized prevention and treatment of RV infection.

The First Case of Para-Bombay Blood Type Encountered in a Korean Tertiary Hospital

Para-Bombay phenotypes are rare blood groups that have inherent defects in producing H antigens associated with FUT1 and/or FUT2. We report the first case of para-Bombay blood type in a Southeast Asian patient admitted at a tertiary hospital in Korea. A 23-year-old Indonesian man presented to the hospital with fever and was diagnosed with a disseminated nontuberculous mycobacterium infection and anemia. During blood group typing for blood transfusion, cell typing showed no agglutination with both anti-A and anti-B reagents. Serum typing showed strong reactivity against B cells and trace agglutination pattern with A1 cells. His red blood cells failed to react with anti-H reagents. Direct sequencing of FUT1 and FUT2 revealed a missense variation, c.328G>A (p.Ala110Thr, rs56342683, FUT1*01W.02), and a synonymous variant, c.390C>T (p.Asn130=, rs281377, Se³⁵⁷), respectively. This highlights the need for both forward and reverse grouping.

Serological characteristics and gene mutation analysis of Para-Bombay blood group / 军事医学

Objective To identify the Para-Bombay blood group on the basis of its serological characteristics .Methods ABO blood typing , H antigen detection , absorption and elution test , and saliva neutralization test were conducted for serological identification of ABO blood group .PCR-SSP was used to sequence FUT1 and FUT2 genes.Results Results of ABO genotyping of eight individuals of the Para-Bombay blood group were consistent with results of their serological blood typing.Among these cases, there were 3 cases of Amh,4 cases of Bmh,and 1 case of Abmh.The results of their FUT1 genotyping were h1h1 in 3 cases, h2h2 in 2 cases and h1h2 in 3 cases.Conclusion The differentce of agglutination intensity between Ac and Bc in reverse ABO blood typing and abnormal Oc agglutination is of greet significance for Para -Bombay blood group.

Estudio de las variantes alélicas del gen FUT2 en una población de Rosario, Santa Fe / Allele of FUT2 gen variables in a population of Rosario, Argentina

El estado secretor de un individuo está determinado por el gen Secretor (FUT2), responsable de la presencia de antígenos ABH en las secreciones del organismo. El polimorfismo del gen FUT2 muestra una gran variabilidad dependiente del tipo de población. Alrededor del 20% de los individuos caucásicos son no­secretores y presentan la mutación G428A. El objetivo de este trabajo fue estudiar las variables alélicas del gen FUT2 en una población de Rosario. Se trabajó con muestras de sangre periférica de dadores voluntarios (n=1728). Se determinó el estado secretor en plasma y saliva y el fenotipo Lewis. El ADN genómico fue extraído por la técnica de salting-out modificada y fue analizado por ASA-PCR con cebadores específicos para el alelo G428A y para el alelo wild type del gen FUT2. Los resultados obtenidos mostraron que el 77% de los individuos investigados fueron secretores y presentaron el fenotipo Lewis Le(a-b+). El polimorfismo G428A estuvo presente en homocigosis en un 7.5%, valor menor al reportado en la bibliografía para la población caucásica. El análisis molecular del gen FUT2 confirmaría la diversidad genética de la población investigada y podría ser utilizada como un marcador poblacional.

The secretor status is determinate by the secretor gene (FUT2) responsible of the ABH antigens expression in human secretions. About 20% of Caucasian individuals are non-secretors. The aim of this study was to study the allelic varieties of the FUT2 gene by a PCR reaction. We worked with peripheral blood samples of volunteers (n= 1728). We determinated the secretor status in plasma and saliva. The genomic DNA was extracted by an enzymatic digestion method and was analyzed by ASA-PCR with specific primers for the G428A allele and for the wild type allele of the FUT2 gene. The results obtained by serologic and molecular methods showed that the 77% of the investigate individuals were secretors. The G428A polymorphism had present in a 7.5%. The allelic varieties of the other non-secretor individuals different to the G428A might to correspond to other mutations. The molecular analysis of the FUT2 gene confirms the genetic diversity of the investigated population.

Evaluation of the Genotypes of the Lewis Blood Group in a Korean Population Using Direct Sequencing / 대한혈액학회지

BACKGROUND: The FUT2 and FUT3 genes determine the Lewis phenotype of red blood cells (RBCs). Recently, the Lewis genes, the secretor genes, and several mutations that cause Lewis negative and nonsecretor phenotypes have been identified. The purpose of this study was to analyze the gene frequency of FUT2 and FUT3 in a Korean population by comparing the use of the direct sequencing method to the use of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mutation detection in the FUT2 and FUT3 genes. METHODS: RBCs and peripheral blood leukocytes were obtained from 225 apparently healthy volunteers to determine the phenotype and genotype of the FUT2 and FUT3 genes. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using the column agglutination method. Lewis blood group genotyping was performed by use of the direct sequencing method. For the detection of T59G, C357T, and A385T mutations, the PCR-RFLP method was performed. RESULTS: The frequencies of the Lewis blood group phenotype were 12.4% for Le(a+b-), 70.7% for Le(a-b+), 11.1% for Le(a-b-) and 5.8% for Le(a+b+), respectively. Direct Sequencing of the FUT2 gene identified 92.2% C357T, 56.9% A385T, 0.4% G244A mutations and 1.8% del396. Direct Sequencing of the FUT3 gene identified 46.9% T59G, 30.4% G508A, 1.1% T202C, 1.1% C314T, 0.7% A1029G, 3.0% T1067A and 13.3% G1242A mutations. The PCR-RFLP method results were discordant in nine cases (1 case for C357T, 4 cases for A385T and 2 cases for T59G) as compared to the direct sequencing method results. CONCLUSION: We have determined the frequencies of FUT2 and FUT3 gene mutations in a Korean population. The use of the direct sequencing method was more accurate than the use of the PCR-RFLP method for the determination of the genotype of the FUT2 and FUT3 genes.

Evaluation of the RBC Lewis Blood Group Phenotypes and Genotypes of the FUT3 and FUT2 Gene / 대한진단검사의학회지

BACKGROUND: The Lewis and secretor gene determine the Lewis phenoytpe. Conventional Lewis blood grouping is difficult because of the presence of nongenuine Lewis negative individuals. Recently, the Lewis gene (FUT3), the secretor gene (FUT2), and several mutations that cause the Lewis negative and the nonsecretor phenotypes were identified. The purpose of this study was to compare Lewis phenotypes determined by commercially available three pairs of monoclonal antibodies with the Lewis and secretor genotypes. METHODS: RBCs for phenotyping and peripheral blood leukocytes for genotyping of FUT3 and FUT2 gene were obtained from 184 apparently healthy volunteers. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using three pairs of commercially available monoclonal antibodies, one of which was the column agglutination method and the others were the tube agglutination methods. Lewis blood group genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to detect T59G, G428A, C357T, and A385T mutations. RESULTS: The frequencies of the Lewis blood group phenotype were Le(a+b-) 15.0%, Le(a-b+) 65.8%, Le(a-b-) 14.8%, and Le(a+b+) 4.3%, respectively. The Lewis blood group phenotypes determined by three pairs of monoclonal antibodies were 93.5%, 93.5% and 89.1% in accordance with the genotypes. The frequencies of Le, le, Se and se alleles were 64.4%, 35.6%, 48.6%, and 51.4% and we have newly detected 4 cases with only one A385T mutation. All of the Le(a+b+) phenotype cases have both C357T, and A385T homozygotic mutations. CONCLUSIONS: The PCR method may be effectively used for the genotyping of the FUT3 and FUT2 genes and offers an attractive alternative to Lewis phenotyping using hemagglutination method.

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.

Molecular genetics analysis and frequency survey of H deficient phenotype / 中国输血杂志

Objective To survey the frequency of H deficient phenotype in blood donor population and analyze the serological and genetic characteristics of these individuals.Methods The H deficient phenotype was screened with anti-H monoclonal antibody.The ABO type was screened with serological method and with sequence specific primer polymerase chain reaction(PCR-SSP).FUT1 and FUT2 gene sequences were analyzed with direct sequencing of PCR products and gene cloning products.Result Of 85 390 blood donors,ten individuals were identified to be para-Bombay phenotype.Four h alleles were found in 14 para-Bombay phenotype individuals,h1(nt547-552?ag),h2(nt880-882?tt),h3(nt658c→t),and h_(new-2)(nt328g→a).The FUT1 genotypes of these para-Bombay individuals were h1/h1(6 individuals),h1/h2(7 individuals) and h3/h_(new2)(1 individual),and the frequency of 4 allele were 67.85%(h1),25%(h2),3.57%(h3),and 3.57%(h_(new-2)),respectively.FUT2 gene was analyzed in 12 para-Bombay phenotype individuals,and a mutation of nt357c→t was detected in all FUT2 gene,another mutation of nt716g→a were heterozygous in 5 individuals with h1/h2 genotype.No null FUT2 gene was detected.In serological analysis,all atypical anti-A or anti-B antibody of 14 para-Bombay individuals were inactive at 37℃,7 individuals had active anti-H antibody at 37℃.Conclusion The frequency of H deficient phenotype in Fujian population is about 1:8 500.The h1 and h2 alleles are predominant in Fujian H deficient individuals on h1-Se~(357) and h2-Se~(357,716) haplotype background.

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

Analysis of four new variant alleles at FUT2 locus / 中国法医学杂志

Objective To investigate the molecular structure, gene expression and detecting methods of some new variant alleles at FUT2 locus. Method We examined four new variant alleles at FUT2 locus using PCR, RFLPs, gene recombination, DNA sequencing and techniques related to gene expression. Results Three missense gene mutations which were C664T, G868A and G760A respectively were found in three New Guinea individuals. Absence of the glycosyltransferase activity in all three enzymes coded by above three missense gene mutations were confirmed by gene expression techniques. Nonsense mutation A660T was found in one Chinese Han individuals. Changing of sequence of endonuclease SacI resulted from C664T and A660T can be detected by RFLP method. Weak peaks of variats might be missed if DNA sequencing was used to detect heterozygotes. RFLP method can't be used to determine specific site of variation within identified sequence of endonuclease. Conclusion All three FUT2 genes resulted from three mutations C664T, G868A, and G760A were non-secretor genes. More than two methods must be used for checking results each other when detect DNA sequence polymorphisms.